Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Name server resolution |
| 3 | * |
| 4 | * Copyright 2014 Baptiste Assmann <bedis9@gmail.com> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU General Public License |
| 8 | * as published by the Free Software Foundation; either version |
| 9 | * 2 of the License, or (at your option) any later version. |
| 10 | * |
| 11 | */ |
| 12 | |
| 13 | #include <errno.h> |
| 14 | #include <fcntl.h> |
| 15 | #include <stdio.h> |
| 16 | #include <stdlib.h> |
| 17 | #include <string.h> |
| 18 | #include <unistd.h> |
| 19 | |
| 20 | #include <sys/types.h> |
| 21 | |
| 22 | #include <common/time.h> |
| 23 | #include <common/ticks.h> |
| 24 | |
Baptiste Assmann | fa4a663 | 2017-05-04 09:05:00 +0200 | [diff] [blame] | 25 | #include <import/lru.h> |
| 26 | #include <import/xxhash.h> |
| 27 | |
William Lallemand | 69e9644 | 2016-11-19 00:58:54 +0100 | [diff] [blame] | 28 | #include <types/applet.h> |
| 29 | #include <types/cli.h> |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 30 | #include <types/global.h> |
| 31 | #include <types/dns.h> |
| 32 | #include <types/proto_udp.h> |
William Lallemand | 69e9644 | 2016-11-19 00:58:54 +0100 | [diff] [blame] | 33 | #include <types/stats.h> |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 34 | |
William Lallemand | 69e9644 | 2016-11-19 00:58:54 +0100 | [diff] [blame] | 35 | #include <proto/channel.h> |
| 36 | #include <proto/cli.h> |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 37 | #include <proto/checks.h> |
| 38 | #include <proto/dns.h> |
| 39 | #include <proto/fd.h> |
| 40 | #include <proto/log.h> |
| 41 | #include <proto/server.h> |
| 42 | #include <proto/task.h> |
| 43 | #include <proto/proto_udp.h> |
William Lallemand | 69e9644 | 2016-11-19 00:58:54 +0100 | [diff] [blame] | 44 | #include <proto/stream_interface.h> |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 45 | |
| 46 | struct list dns_resolvers = LIST_HEAD_INIT(dns_resolvers); |
| 47 | struct dns_resolution *resolution = NULL; |
| 48 | |
| 49 | static int64_t dns_query_id_seed; /* random seed */ |
| 50 | |
Baptiste Assmann | fa4a663 | 2017-05-04 09:05:00 +0200 | [diff] [blame] | 51 | static struct lru64_head *dns_lru_tree; |
| 52 | static int dns_cache_size = 1024; /* arbitrary DNS cache size */ |
| 53 | |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 54 | /* proto_udp callback functions for a DNS resolution */ |
| 55 | struct dgram_data_cb resolve_dgram_cb = { |
| 56 | .recv = dns_resolve_recv, |
| 57 | .send = dns_resolve_send, |
| 58 | }; |
| 59 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 60 | /* local function prototypes */ |
| 61 | static int dns_run_resolution(struct dns_requester *requester); |
| 62 | |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 63 | #if DEBUG |
| 64 | /* |
| 65 | * go through the resolutions associated to a resolvers section and print the ID and hostname in |
| 66 | * domain name format |
| 67 | * should be used for debug purpose only |
| 68 | */ |
| 69 | void dns_print_current_resolutions(struct dns_resolvers *resolvers) |
| 70 | { |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 71 | list_for_each_entry(resolution, &resolvers->resolution.curr, list) { |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 72 | printf(" resolution %d for %s\n", resolution->query_id, resolution->hostname_dn); |
| 73 | } |
| 74 | } |
| 75 | #endif |
| 76 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 77 | void dump_dns_config() |
| 78 | { |
| 79 | struct dns_resolvers *curr_resolvers = NULL; |
| 80 | struct dns_nameserver *curr_nameserver = NULL; |
| 81 | struct dns_resolution *curr_resolution = NULL; |
| 82 | struct dns_requester *curr_requester = NULL; |
| 83 | |
| 84 | printf("===============\n"); |
| 85 | list_for_each_entry(curr_resolvers, &dns_resolvers, list) { |
| 86 | printf("Resolvers: %s\n", curr_resolvers->id); |
| 87 | |
| 88 | printf(" nameservers:\n"); |
| 89 | list_for_each_entry(curr_nameserver, &curr_resolvers->nameserver_list, list) { |
| 90 | printf(" %s\n", curr_nameserver->id); |
| 91 | } |
| 92 | |
| 93 | /* |
| 94 | printf(" resolution.pool list:\n"); |
| 95 | list_for_each_entry(curr_resolution, &curr_resolvers->resolution.pool, list) { |
| 96 | printf(" %p\n", curr_resolution); |
| 97 | } |
| 98 | */ |
| 99 | |
| 100 | printf(" resolution.wait list:\n"); |
| 101 | list_for_each_entry(curr_resolution, &curr_resolvers->resolution.wait, list) { |
| 102 | printf(" %p %s\n", curr_resolution, curr_resolution->hostname_dn); |
| 103 | printf(" requester.wait list:\n"); |
| 104 | list_for_each_entry(curr_requester, &curr_resolution->requester.wait, list) { |
| 105 | printf(" %p %s %d\n", curr_requester, objt_server(curr_requester->requester)->id, curr_requester->prefered_query_type); |
| 106 | } |
| 107 | printf(" requester.curr list:\n"); |
| 108 | list_for_each_entry(curr_requester, &curr_resolution->requester.curr, list) { |
| 109 | printf(" %p %s %d\n", curr_requester, objt_server(curr_requester->requester)->id, curr_requester->prefered_query_type); |
| 110 | } |
| 111 | } |
| 112 | printf(" resolution.curr list:\n"); |
| 113 | list_for_each_entry(curr_resolution, &curr_resolvers->resolution.curr, list) { |
| 114 | printf(" %p %s\n", curr_resolution, curr_resolution->hostname_dn); |
| 115 | printf(" requester.wait list:\n"); |
| 116 | list_for_each_entry(curr_requester, &curr_resolution->requester.wait, list) { |
| 117 | printf(" %p %s %d\n", curr_requester, objt_server(curr_requester->requester)->id, curr_requester->prefered_query_type); |
| 118 | } |
| 119 | printf(" requester.curr list:\n"); |
| 120 | list_for_each_entry(curr_requester, &curr_resolution->requester.curr, list) { |
| 121 | printf(" %p %s %d\n", curr_requester, objt_server(curr_requester->requester)->id, curr_requester->prefered_query_type); |
| 122 | } |
| 123 | } |
| 124 | } |
| 125 | |
| 126 | printf("===============\n"); |
| 127 | } |
| 128 | |
| 129 | /* |
| 130 | * Initiates a new name resolution: |
| 131 | * - generates a query id |
| 132 | * - configure the resolution structure |
| 133 | * - startup the resolvers task if required |
| 134 | * |
| 135 | * returns: |
| 136 | * - 0 if everything started properly |
| 137 | * - -1 in case of error or if resolution already running |
| 138 | */ |
| 139 | int dns_trigger_resolution(struct dns_resolution *resolution) |
| 140 | { |
| 141 | struct dns_requester *requester = NULL, *tmprequester; |
| 142 | struct dns_resolvers *resolvers = NULL; |
| 143 | int inter; |
| 144 | |
| 145 | /* process the element of the wait queue */ |
| 146 | list_for_each_entry_safe(requester, tmprequester, &resolution->requester.wait, list) { |
| 147 | inter = 0; |
| 148 | |
| 149 | switch (obj_type(requester->requester)) { |
| 150 | case OBJ_TYPE_SERVER: |
| 151 | inter = objt_server(requester->requester)->check.inter; |
| 152 | resolvers = objt_server(requester->requester)->resolvers; |
| 153 | break; |
| 154 | case OBJ_TYPE_NONE: |
| 155 | default: |
| 156 | return -1; |
| 157 | } |
| 158 | |
| 159 | /* if data is fresh enough, let's use it */ |
| 160 | if (!tick_is_expired(tick_add(resolution->last_resolution, inter), now_ms)) { |
| 161 | /* we only use cache if the response there is valid. |
| 162 | * If not valid, we run the resolution and move the requester to |
| 163 | * the run queue. */ |
| 164 | if (resolution->status != RSLV_STATUS_VALID) { |
| 165 | LIST_DEL(&requester->list); |
| 166 | LIST_ADDQ(&resolution->requester.curr, &requester->list); |
| 167 | dns_run_resolution(requester); |
| 168 | continue; |
| 169 | } |
| 170 | |
| 171 | requester->requester_cb(requester, NULL); |
| 172 | } |
| 173 | else { |
| 174 | LIST_DEL(&requester->list); |
| 175 | LIST_ADDQ(&resolution->requester.curr, &requester->list); |
| 176 | dns_run_resolution(requester); |
| 177 | } |
| 178 | } |
| 179 | |
| 180 | if (resolvers) |
| 181 | dns_update_resolvers_timeout(resolvers); |
| 182 | |
| 183 | return 0; |
| 184 | } |
| 185 | |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 186 | /* |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 187 | * Prepare and send a DNS resolution. |
| 188 | * |
| 189 | * Return code: |
| 190 | * - 0 if no error occured |
| 191 | * - -1 in case of error |
| 192 | */ |
| 193 | static int |
| 194 | dns_run_resolution(struct dns_requester *requester) |
| 195 | { |
| 196 | struct dns_resolution *resolution; |
| 197 | struct dns_resolvers *resolvers; |
| 198 | int query_id, query_type, i; |
| 199 | struct proxy *proxy; |
| 200 | |
| 201 | resolution = NULL; |
| 202 | resolvers = NULL; |
| 203 | proxy = NULL; |
| 204 | query_type = -1; |
| 205 | switch (obj_type(requester->requester)) { |
| 206 | case OBJ_TYPE_SERVER: |
| 207 | resolution = objt_server(requester->requester)->resolution; |
| 208 | resolvers = objt_server(requester->requester)->resolvers; |
| 209 | proxy = objt_server(requester->requester)->proxy; |
| 210 | query_type = requester->prefered_query_type; |
| 211 | break; |
| 212 | case OBJ_TYPE_NONE: |
| 213 | default: |
| 214 | return -1; |
| 215 | } |
| 216 | |
| 217 | /* |
| 218 | * check if a resolution has already been started for this server |
| 219 | * return directly to avoid resolution pill up. |
| 220 | */ |
| 221 | if (resolution->step != RSLV_STEP_NONE) |
| 222 | return 0; |
| 223 | |
| 224 | /* generates a query id */ |
| 225 | i = 0; |
| 226 | do { |
| 227 | query_id = dns_rnd16(); |
| 228 | /* we do try only 100 times to find a free query id */ |
| 229 | if (i++ > 100) { |
| 230 | chunk_printf(&trash, "could not generate a query id for %s, in resolvers %s", |
| 231 | resolution->hostname_dn, resolvers->id); |
| 232 | |
| 233 | if (proxy) |
| 234 | send_log(proxy, LOG_NOTICE, "%s.\n", trash.str); |
| 235 | return -1; |
| 236 | } |
| 237 | } while (eb32_lookup(&resolvers->query_ids, query_id)); |
| 238 | |
| 239 | /* move the resolution into the run queue */ |
| 240 | LIST_DEL(&resolution->list); |
| 241 | LIST_ADDQ(&resolvers->resolution.curr, &resolution->list); |
| 242 | |
| 243 | /* now update resolution parameters */ |
| 244 | resolution->query_id = query_id; |
| 245 | resolution->qid.key = query_id; |
| 246 | resolution->step = RSLV_STEP_RUNNING; |
| 247 | resolution->query_type = query_type; |
| 248 | resolution->try = resolvers->resolve_retries; |
| 249 | resolution->try_cname = 0; |
| 250 | resolution->nb_responses = 0; |
| 251 | eb32_insert(&resolvers->query_ids, &resolution->qid); |
| 252 | |
| 253 | dns_send_query(resolution); |
| 254 | resolution->try -= 1; |
| 255 | |
| 256 | /* update wakeup date if this resolution is the only one in the FIFO list */ |
| 257 | if (dns_check_resolution_queue(resolvers) == 1) { |
| 258 | /* update task timeout */ |
| 259 | dns_update_resolvers_timeout(resolvers); |
| 260 | task_queue(resolvers->t); |
| 261 | } |
| 262 | |
| 263 | return 0; |
| 264 | } |
| 265 | |
| 266 | /* |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 267 | * check if there is more than 1 resolution in the resolver's resolution list |
| 268 | * return value: |
| 269 | * 0: empty list |
| 270 | * 1: exactly one entry in the list |
| 271 | * 2: more than one entry in the list |
| 272 | */ |
| 273 | int dns_check_resolution_queue(struct dns_resolvers *resolvers) |
| 274 | { |
| 275 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 276 | if (LIST_ISEMPTY(&resolvers->resolution.curr)) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 277 | return 0; |
| 278 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 279 | if ((resolvers->resolution.curr.n) && (resolvers->resolution.curr.n == resolvers->resolution.curr.p)) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 280 | return 1; |
| 281 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 282 | if (! ((resolvers->resolution.curr.n == resolvers->resolution.curr.p) |
| 283 | && (&resolvers->resolution.curr != resolvers->resolution.curr.n))) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 284 | return 2; |
| 285 | |
| 286 | return 0; |
| 287 | } |
| 288 | |
| 289 | /* |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 290 | * reset some resolution parameters to initial values and also delete the |
| 291 | * query ID from the resolver's tree. |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 292 | */ |
| 293 | void dns_reset_resolution(struct dns_resolution *resolution) |
| 294 | { |
| 295 | /* update resolution status */ |
| 296 | resolution->step = RSLV_STEP_NONE; |
| 297 | |
| 298 | resolution->try = 0; |
| 299 | resolution->try_cname = 0; |
| 300 | resolution->last_resolution = now_ms; |
| 301 | resolution->nb_responses = 0; |
| 302 | |
| 303 | /* clean up query id */ |
| 304 | eb32_delete(&resolution->qid); |
| 305 | resolution->query_id = 0; |
| 306 | resolution->qid.key = 0; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 307 | } |
| 308 | |
| 309 | /* |
| 310 | * function called when a network IO is generated on a name server socket for an incoming packet |
| 311 | * It performs the following actions: |
| 312 | * - check if the packet requires processing (not outdated resolution) |
| 313 | * - ensure the DNS packet received is valid and call requester's callback |
| 314 | * - call requester's error callback if invalid response |
Baptiste Assmann | 3cf7f98 | 2016-04-17 22:43:26 +0200 | [diff] [blame] | 315 | * - check the dn_name in the packet against the one sent |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 316 | */ |
| 317 | void dns_resolve_recv(struct dgram_conn *dgram) |
| 318 | { |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 319 | struct dns_nameserver *nameserver, *tmpnameserver; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 320 | struct dns_resolvers *resolvers; |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 321 | struct dns_resolution *resolution = NULL; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 322 | struct dns_query_item *query; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 323 | unsigned char buf[DNS_MAX_UDP_MESSAGE + 1]; |
| 324 | unsigned char *bufend; |
William Lallemand | cc9b94a | 2017-06-08 19:30:39 +0200 | [diff] [blame] | 325 | int fd, buflen, dns_resp, need_resend = 0; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 326 | unsigned short query_id; |
| 327 | struct eb32_node *eb; |
Baptiste Assmann | fa4a663 | 2017-05-04 09:05:00 +0200 | [diff] [blame] | 328 | struct lru64 *lru = NULL; |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 329 | struct dns_requester *requester = NULL, *tmprequester = NULL; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 330 | |
| 331 | fd = dgram->t.sock.fd; |
| 332 | |
| 333 | /* check if ready for reading */ |
| 334 | if (!fd_recv_ready(fd)) |
| 335 | return; |
| 336 | |
| 337 | /* no need to go further if we can't retrieve the nameserver */ |
Vincent Bernat | 3c2f2f2 | 2016-04-03 13:48:42 +0200 | [diff] [blame] | 338 | if ((nameserver = dgram->owner) == NULL) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 339 | return; |
| 340 | |
| 341 | resolvers = nameserver->resolvers; |
| 342 | |
| 343 | /* process all pending input messages */ |
| 344 | while (1) { |
| 345 | /* read message received */ |
| 346 | memset(buf, '\0', DNS_MAX_UDP_MESSAGE + 1); |
| 347 | if ((buflen = recv(fd, (char*)buf , DNS_MAX_UDP_MESSAGE, 0)) < 0) { |
| 348 | /* FIXME : for now we consider EAGAIN only */ |
| 349 | fd_cant_recv(fd); |
| 350 | break; |
| 351 | } |
| 352 | |
| 353 | /* message too big */ |
| 354 | if (buflen > DNS_MAX_UDP_MESSAGE) { |
| 355 | nameserver->counters.too_big += 1; |
| 356 | continue; |
| 357 | } |
| 358 | |
| 359 | /* initializing variables */ |
| 360 | bufend = buf + buflen; /* pointer to mark the end of the buffer */ |
| 361 | |
| 362 | /* read the query id from the packet (16 bits) */ |
| 363 | if (buf + 2 > bufend) { |
| 364 | nameserver->counters.invalid += 1; |
| 365 | continue; |
| 366 | } |
| 367 | query_id = dns_response_get_query_id(buf); |
| 368 | |
| 369 | /* search the query_id in the pending resolution tree */ |
Baptiste Assmann | 01daef3 | 2015-09-02 22:05:24 +0200 | [diff] [blame] | 370 | eb = eb32_lookup(&resolvers->query_ids, query_id); |
| 371 | if (eb == NULL) { |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 372 | /* unknown query id means an outdated response and can be safely ignored */ |
| 373 | nameserver->counters.outdated += 1; |
| 374 | continue; |
| 375 | } |
| 376 | |
| 377 | /* known query id means a resolution in prgress */ |
| 378 | resolution = eb32_entry(eb, struct dns_resolution, qid); |
| 379 | |
| 380 | if (!resolution) { |
| 381 | nameserver->counters.outdated += 1; |
| 382 | continue; |
| 383 | } |
| 384 | |
| 385 | /* number of responses received */ |
| 386 | resolution->nb_responses += 1; |
| 387 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 388 | dns_resp = dns_validate_dns_response(buf, bufend, resolution); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 389 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 390 | switch (dns_resp) { |
| 391 | case DNS_RESP_VALID: |
| 392 | need_resend = 0; |
| 393 | break; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 394 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 395 | case DNS_RESP_INVALID: |
| 396 | case DNS_RESP_QUERY_COUNT_ERROR: |
| 397 | case DNS_RESP_WRONG_NAME: |
| 398 | if (resolution->status != RSLV_STATUS_INVALID) { |
| 399 | resolution->status = RSLV_STATUS_INVALID; |
| 400 | resolution->last_status_change = now_ms; |
| 401 | } |
| 402 | nameserver->counters.invalid += 1; |
| 403 | need_resend = 0; |
| 404 | break; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 405 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 406 | case DNS_RESP_ANCOUNT_ZERO: |
| 407 | if (resolution->status != RSLV_STATUS_OTHER) { |
| 408 | resolution->status = RSLV_STATUS_OTHER; |
| 409 | resolution->last_status_change = now_ms; |
| 410 | } |
| 411 | nameserver->counters.any_err += 1; |
| 412 | need_resend = 1; |
| 413 | break; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 414 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 415 | case DNS_RESP_NX_DOMAIN: |
| 416 | if (resolution->status != RSLV_STATUS_NX) { |
| 417 | resolution->status = RSLV_STATUS_NX; |
| 418 | resolution->last_status_change = now_ms; |
| 419 | } |
| 420 | nameserver->counters.nx += 1; |
| 421 | need_resend = 0; |
| 422 | break; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 423 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 424 | case DNS_RESP_REFUSED: |
| 425 | if (resolution->status != RSLV_STATUS_REFUSED) { |
| 426 | resolution->status = RSLV_STATUS_REFUSED; |
| 427 | resolution->last_status_change = now_ms; |
| 428 | } |
| 429 | nameserver->counters.refused += 1; |
| 430 | need_resend = 0; |
| 431 | break; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 432 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 433 | case DNS_RESP_CNAME_ERROR: |
| 434 | if (resolution->status != RSLV_STATUS_OTHER) { |
| 435 | resolution->status = RSLV_STATUS_OTHER; |
| 436 | resolution->last_status_change = now_ms; |
| 437 | } |
| 438 | nameserver->counters.cname_error += 1; |
| 439 | need_resend = 1; |
| 440 | break; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 441 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 442 | case DNS_RESP_TRUNCATED: |
| 443 | if (resolution->status != RSLV_STATUS_OTHER) { |
| 444 | resolution->status = RSLV_STATUS_OTHER; |
| 445 | resolution->last_status_change = now_ms; |
| 446 | } |
| 447 | nameserver->counters.truncated += 1; |
| 448 | need_resend = 1; |
| 449 | break; |
Baptiste Assmann | 96972bc | 2015-09-09 00:46:58 +0200 | [diff] [blame] | 450 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 451 | case DNS_RESP_NO_EXPECTED_RECORD: |
| 452 | if (resolution->status != RSLV_STATUS_OTHER) { |
| 453 | resolution->status = RSLV_STATUS_OTHER; |
| 454 | resolution->last_status_change = now_ms; |
| 455 | } |
| 456 | nameserver->counters.other += 1; |
| 457 | need_resend = 1; |
| 458 | break; |
| 459 | |
| 460 | case DNS_RESP_ERROR: |
| 461 | case DNS_RESP_INTERNAL: |
| 462 | if (resolution->status != RSLV_STATUS_OTHER) { |
| 463 | resolution->status = RSLV_STATUS_OTHER; |
| 464 | resolution->last_status_change = now_ms; |
| 465 | } |
| 466 | nameserver->counters.other += 1; |
| 467 | need_resend = 1; |
| 468 | break; |
| 469 | } |
| 470 | |
| 471 | /* some error codes trigger a re-send of the query, but switching the |
| 472 | * query type. |
| 473 | * This is the case for the following error codes: |
| 474 | * DNS_RESP_ANCOUNT_ZERO |
| 475 | * DNS_RESP_TRUNCATED |
| 476 | * DNS_RESP_ERROR |
| 477 | * DNS_RESP_INTERNAL |
| 478 | * DNS_RESP_NO_EXPECTED_RECORD |
| 479 | * DNS_RESP_CNAME_ERROR |
| 480 | */ |
| 481 | if (need_resend) { |
| 482 | int family_prio; |
| 483 | int res_preferred_afinet, res_preferred_afinet6; |
| 484 | |
| 485 | requester = LIST_NEXT(&resolution->requester.curr, struct dns_requester *, list); |
| 486 | switch (obj_type(requester->requester)) { |
| 487 | case OBJ_TYPE_SERVER: |
| 488 | family_prio = objt_server(requester->requester)->dns_opts.family_prio; |
| 489 | break; |
| 490 | case OBJ_TYPE_NONE: |
| 491 | default: |
| 492 | family_prio = AF_INET6; |
| 493 | } |
| 494 | res_preferred_afinet = family_prio == AF_INET && resolution->query_type == DNS_RTYPE_A; |
| 495 | res_preferred_afinet6 = family_prio == AF_INET6 && resolution->query_type == DNS_RTYPE_AAAA; |
| 496 | if ((res_preferred_afinet || res_preferred_afinet6) |
| 497 | || (resolution->try > 0)) { |
| 498 | /* let's change the query type */ |
| 499 | if (res_preferred_afinet6) { |
| 500 | /* fallback from AAAA to A */ |
| 501 | resolution->query_type = DNS_RTYPE_A; |
| 502 | } |
| 503 | else if (res_preferred_afinet) { |
| 504 | /* fallback from A to AAAA */ |
| 505 | resolution->query_type = DNS_RTYPE_AAAA; |
| 506 | } |
| 507 | else { |
| 508 | resolution->try -= 1; |
| 509 | if (family_prio == AF_INET) { |
| 510 | resolution->query_type = DNS_RTYPE_A; |
| 511 | } else { |
| 512 | resolution->query_type = DNS_RTYPE_AAAA; |
| 513 | } |
| 514 | } |
| 515 | |
| 516 | dns_send_query(resolution); |
| 517 | /* |
| 518 | * move the resolution to the last element of the FIFO queue |
| 519 | * and update timeout wakeup based on the new first entry |
| 520 | */ |
| 521 | if (dns_check_resolution_queue(resolvers) > 1) { |
| 522 | /* second resolution becomes first one */ |
| 523 | LIST_DEL(&resolution->list); |
| 524 | /* ex first resolution goes to the end of the queue */ |
| 525 | LIST_ADDQ(&resolvers->resolution.curr, &resolution->list); |
| 526 | } |
| 527 | |
| 528 | dns_update_resolvers_timeout(resolvers); |
| 529 | goto next_packet; |
| 530 | } |
| 531 | |
| 532 | /* if we're there, this means that we already ran out of chances to re-send |
| 533 | * the query */ |
| 534 | list_for_each_entry_safe(requester, tmprequester, &resolution->requester.curr, list) { |
| 535 | requester->requester_error_cb(requester, dns_resp); |
| 536 | } |
| 537 | goto next_packet; |
| 538 | } |
| 539 | |
| 540 | /* now processing those error codes only: |
| 541 | * DNS_RESP_NX_DOMAIN |
| 542 | * DNS_RESP_REFUSED |
| 543 | */ |
| 544 | if (dns_resp != DNS_RESP_VALID) { |
| 545 | /* now parse list of requesters currently waiting for this resolution */ |
| 546 | list_for_each_entry_safe(requester, tmprequester, &resolution->requester.curr, list) { |
| 547 | requester->requester_error_cb(requester, dns_resp); |
| 548 | |
| 549 | /* we can move the requester the wait queue */ |
| 550 | LIST_DEL(&requester->list); |
| 551 | LIST_ADDQ(&resolution->requester.wait, &requester->list); |
| 552 | } |
| 553 | goto next_packet; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 554 | } |
| 555 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 556 | /* Now let's check the query's dname corresponds to the one we sent. |
| 557 | * We can check only the first query of the list. We send one query at a time |
| 558 | * so we get one query in the response */ |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 559 | query = LIST_NEXT(&resolution->response.query_list, struct dns_query_item *, list); |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 560 | if (query && memcmp(query->name, resolution->hostname_dn, resolution->hostname_dn_len) != 0) { |
| 561 | nameserver->counters.other += 1; |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 562 | /* now parse list of requesters currently waiting for this resolution */ |
| 563 | list_for_each_entry_safe(requester, tmprequester, &resolution->requester.curr, list) { |
| 564 | requester->requester_error_cb(requester, DNS_RESP_WRONG_NAME); |
| 565 | /* we can move the requester the wait queue */ |
| 566 | LIST_DEL(&requester->list); |
| 567 | LIST_ADDQ(&resolution->requester.wait, &requester->list); |
| 568 | } |
| 569 | goto next_packet; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 570 | } |
| 571 | |
Baptiste Assmann | fa4a663 | 2017-05-04 09:05:00 +0200 | [diff] [blame] | 572 | /* no errors, we can save the response in the cache */ |
| 573 | if (dns_lru_tree) { |
| 574 | unsigned long long seed = 1; |
| 575 | struct chunk *buf = get_trash_chunk(); |
| 576 | struct chunk *tmp = NULL; |
| 577 | |
| 578 | chunk_reset(buf); |
| 579 | tmp = dns_cache_key(resolution->query_type, resolution->hostname_dn, |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 580 | resolution->hostname_dn_len, buf); |
Baptiste Assmann | fa4a663 | 2017-05-04 09:05:00 +0200 | [diff] [blame] | 581 | if (!tmp) { |
| 582 | nameserver->counters.other += 1; |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 583 | /* now parse list of requesters currently waiting for this resolution */ |
| 584 | list_for_each_entry_safe(requester, tmprequester, &resolution->requester.curr, list) { |
| 585 | requester->requester_error_cb(requester, DNS_RESP_ERROR); |
| 586 | /* we can move the requester the wait queue */ |
| 587 | LIST_DEL(&requester->list); |
| 588 | LIST_ADDQ(&resolution->requester.wait, &requester->list); |
| 589 | } |
| 590 | goto next_packet; |
Baptiste Assmann | fa4a663 | 2017-05-04 09:05:00 +0200 | [diff] [blame] | 591 | } |
| 592 | |
| 593 | lru = lru64_get(XXH64(buf->str, buf->len, seed), |
| 594 | dns_lru_tree, nameserver->resolvers, 1); |
| 595 | |
| 596 | lru64_commit(lru, resolution, nameserver->resolvers, 1, NULL); |
| 597 | } |
| 598 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 599 | if (resolution->status != RSLV_STATUS_VALID) { |
| 600 | resolution->status = RSLV_STATUS_VALID; |
| 601 | resolution->last_status_change = now_ms; |
| 602 | } |
| 603 | |
Baptiste Assmann | 37bb372 | 2015-08-07 10:18:32 +0200 | [diff] [blame] | 604 | nameserver->counters.valid += 1; |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 605 | /* now parse list of requesters currently waiting for this resolution */ |
| 606 | tmpnameserver = nameserver; |
| 607 | list_for_each_entry_safe(requester, tmprequester, &resolution->requester.curr, list) { |
| 608 | requester->requester_cb(requester, tmpnameserver); |
| 609 | /* we can move the requester the wait queue */ |
| 610 | LIST_DEL(&requester->list); |
| 611 | LIST_ADDQ(&resolution->requester.wait, &requester->list); |
| 612 | /* first response is managed by the server, others are from the cache */ |
| 613 | tmpnameserver = NULL; |
| 614 | } |
| 615 | |
| 616 | next_packet: |
| 617 | /* resolution may be NULL when we receive an ICMP unreachable packet */ |
| 618 | if (resolution && LIST_ISEMPTY(&resolution->requester.curr)) { |
| 619 | /* move the resolution into the wait queue */ |
| 620 | LIST_DEL(&resolution->list); |
| 621 | LIST_ADDQ(&resolvers->resolution.wait, &resolution->list); |
| 622 | /* update last resolution date and time */ |
| 623 | resolution->last_resolution = now_ms; |
| 624 | /* reset current status flag */ |
| 625 | resolution->step = RSLV_STEP_NONE; |
| 626 | /* reset values */ |
| 627 | dns_reset_resolution(resolution); |
| 628 | } |
| 629 | |
| 630 | } // end of while "packets" loop |
| 631 | |
| 632 | dns_update_resolvers_timeout(nameserver->resolvers); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 633 | } |
| 634 | |
| 635 | /* |
| 636 | * function called when a resolvers network socket is ready to send data |
| 637 | * It performs the following actions: |
| 638 | */ |
| 639 | void dns_resolve_send(struct dgram_conn *dgram) |
| 640 | { |
| 641 | int fd; |
| 642 | struct dns_nameserver *nameserver; |
| 643 | struct dns_resolvers *resolvers; |
| 644 | struct dns_resolution *resolution; |
| 645 | |
| 646 | fd = dgram->t.sock.fd; |
| 647 | |
| 648 | /* check if ready for sending */ |
| 649 | if (!fd_send_ready(fd)) |
| 650 | return; |
| 651 | |
| 652 | /* we don't want/need to be waked up any more for sending */ |
| 653 | fd_stop_send(fd); |
| 654 | |
| 655 | /* no need to go further if we can't retrieve the nameserver */ |
Vincent Bernat | 3c2f2f2 | 2016-04-03 13:48:42 +0200 | [diff] [blame] | 656 | if ((nameserver = dgram->owner) == NULL) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 657 | return; |
| 658 | |
| 659 | resolvers = nameserver->resolvers; |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 660 | resolution = LIST_NEXT(&resolvers->resolution.curr, struct dns_resolution *, list); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 661 | |
| 662 | dns_send_query(resolution); |
| 663 | dns_update_resolvers_timeout(resolvers); |
| 664 | } |
| 665 | |
| 666 | /* |
| 667 | * forge and send a DNS query to resolvers associated to a resolution |
| 668 | * It performs the following actions: |
| 669 | * returns: |
| 670 | * 0 in case of error or safe ignorance |
| 671 | * 1 if no error |
| 672 | */ |
| 673 | int dns_send_query(struct dns_resolution *resolution) |
| 674 | { |
Baptiste Assmann | 4274637 | 2017-05-03 12:12:02 +0200 | [diff] [blame] | 675 | struct dns_resolvers *resolvers = NULL; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 676 | struct dns_nameserver *nameserver; |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 677 | struct dns_requester *requester = NULL; |
Erwan Velu | 5457eb4 | 2015-10-15 15:07:26 +0200 | [diff] [blame] | 678 | int ret, bufsize, fd; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 679 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 680 | /* nothing to do */ |
| 681 | if (LIST_ISEMPTY(&resolution->requester.curr)) |
| 682 | return 0; |
| 683 | |
| 684 | requester = LIST_NEXT(&resolution->requester.curr, struct dns_requester *, list); |
| 685 | |
| 686 | switch (obj_type(requester->requester)) { |
| 687 | case OBJ_TYPE_SERVER: |
| 688 | resolvers = objt_server(requester->requester)->resolvers; |
| 689 | break; |
| 690 | case OBJ_TYPE_NONE: |
| 691 | default: |
| 692 | return 0; |
| 693 | } |
Baptiste Assmann | 4274637 | 2017-05-03 12:12:02 +0200 | [diff] [blame] | 694 | |
| 695 | if (!resolvers) |
| 696 | return 0; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 697 | |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 698 | bufsize = dns_build_query(resolution->query_id, resolution->query_type, resolution->hostname_dn, |
| 699 | resolution->hostname_dn_len, trash.str, trash.size); |
| 700 | |
| 701 | if (bufsize == -1) |
| 702 | return 0; |
| 703 | |
| 704 | list_for_each_entry(nameserver, &resolvers->nameserver_list, list) { |
| 705 | fd = nameserver->dgram->t.sock.fd; |
| 706 | errno = 0; |
| 707 | |
| 708 | ret = send(fd, trash.str, bufsize, 0); |
| 709 | |
| 710 | if (ret > 0) |
| 711 | nameserver->counters.sent += 1; |
| 712 | |
| 713 | if (ret == 0 || errno == EAGAIN) { |
| 714 | /* nothing written, let's update the poller that we wanted to send |
| 715 | * but we were not able to */ |
| 716 | fd_want_send(fd); |
| 717 | fd_cant_send(fd); |
| 718 | } |
| 719 | } |
| 720 | |
| 721 | /* update resolution */ |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 722 | resolution->nb_responses = 0; |
| 723 | resolution->last_sent_packet = now_ms; |
| 724 | |
| 725 | return 1; |
| 726 | } |
| 727 | |
| 728 | /* |
| 729 | * update a resolvers' task timeout for next wake up |
| 730 | */ |
| 731 | void dns_update_resolvers_timeout(struct dns_resolvers *resolvers) |
| 732 | { |
| 733 | struct dns_resolution *resolution; |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 734 | struct dns_requester *requester; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 735 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 736 | if ((LIST_ISEMPTY(&resolvers->resolution.curr)) && (LIST_ISEMPTY(&resolvers->resolution.wait))) { |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 737 | resolvers->t->expire = TICK_ETERNITY; |
| 738 | } |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 739 | else if (!LIST_ISEMPTY(&resolvers->resolution.curr)) { |
| 740 | resolution = LIST_NEXT(&resolvers->resolution.curr, struct dns_resolution *, list); |
| 741 | if (!resolvers->t->expire || tick_is_le(resolvers->t->expire, tick_add(resolution->last_sent_packet, resolvers->timeout.retry))) { |
| 742 | resolvers->t->expire = tick_add(resolution->last_sent_packet, resolvers->timeout.retry); |
| 743 | } |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 744 | } |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 745 | else if (!LIST_ISEMPTY(&resolvers->resolution.wait)) { |
| 746 | int valid_period, inter, need_wakeup; |
| 747 | struct dns_resolution *res_back; |
| 748 | need_wakeup = 0; |
| 749 | list_for_each_entry_safe(resolution, res_back, &resolvers->resolution.wait, list) { |
| 750 | valid_period = 0; |
| 751 | inter = 0; |
| 752 | |
| 753 | requester = LIST_NEXT(&resolution->requester.wait, struct dns_requester *, list); |
| 754 | |
| 755 | switch (obj_type(requester->requester)) { |
| 756 | case OBJ_TYPE_SERVER: |
| 757 | valid_period = objt_server(requester->requester)->check.inter; |
| 758 | break; |
| 759 | case OBJ_TYPE_NONE: |
| 760 | default: |
| 761 | continue; |
| 762 | } |
| 763 | |
| 764 | if (resolvers->hold.valid < valid_period) |
| 765 | inter = resolvers->hold.valid; |
| 766 | else |
| 767 | inter = valid_period; |
| 768 | |
| 769 | if (tick_is_expired(tick_add(resolution->last_resolution, inter), now_ms)) { |
| 770 | switch (obj_type(requester->requester)) { |
| 771 | case OBJ_TYPE_SERVER: |
| 772 | dns_trigger_resolution(objt_server(requester->requester)->resolution); |
| 773 | break; |
| 774 | case OBJ_TYPE_NONE: |
| 775 | default: |
| 776 | ;; |
| 777 | } |
| 778 | } |
| 779 | else { |
| 780 | need_wakeup = 1; |
| 781 | } |
| 782 | } |
| 783 | /* in such case, we wake up in 1s */ |
| 784 | if (need_wakeup) { |
| 785 | int r = 1000; |
| 786 | |
| 787 | resolution = LIST_NEXT(&resolvers->resolution.wait, struct dns_resolution *, list); |
| 788 | if (tick_is_le(resolvers->t->expire, tick_add(now_ms, r))) |
| 789 | resolvers->t->expire = tick_add(now_ms, r); |
| 790 | resolvers->t->expire = tick_add(now_ms, 1000); |
| 791 | } |
| 792 | } |
| 793 | |
| 794 | task_queue(resolvers->t); |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 795 | } |
| 796 | |
| 797 | /* |
| 798 | * Analyse, re-build and copy the name <name> from the DNS response packet <buffer>. |
| 799 | * <name> must point to the 'data_len' information or pointer 'c0' for compressed data. |
| 800 | * The result is copied into <dest>, ensuring we don't overflow using <dest_len> |
| 801 | * Returns the number of bytes the caller can move forward. If 0 it means an error occured |
| 802 | * while parsing the name. |
| 803 | * <offset> is the number of bytes the caller could move forward. |
| 804 | */ |
| 805 | int dns_read_name(unsigned char *buffer, unsigned char *bufend, unsigned char *name, char *destination, int dest_len, int *offset) |
| 806 | { |
| 807 | int nb_bytes = 0, n = 0; |
| 808 | int label_len; |
| 809 | unsigned char *reader = name; |
| 810 | char *dest = destination; |
| 811 | |
| 812 | while (1) { |
| 813 | /* name compression is in use */ |
| 814 | if ((*reader & 0xc0) == 0xc0) { |
| 815 | /* a pointer must point BEFORE current position */ |
| 816 | if ((buffer + reader[1]) > reader) { |
| 817 | goto out_error; |
| 818 | } |
| 819 | |
| 820 | n = dns_read_name(buffer, bufend, buffer + reader[1], dest, dest_len - nb_bytes, offset); |
| 821 | if (n == 0) |
| 822 | goto out_error; |
| 823 | |
| 824 | dest += n; |
| 825 | nb_bytes += n; |
| 826 | goto out; |
| 827 | } |
| 828 | |
| 829 | label_len = *reader; |
| 830 | if (label_len == 0) |
| 831 | goto out; |
| 832 | /* Check if: |
| 833 | * - we won't read outside the buffer |
| 834 | * - there is enough place in the destination |
| 835 | */ |
| 836 | if ((reader + label_len >= bufend) || (nb_bytes + label_len >= dest_len)) |
| 837 | goto out_error; |
| 838 | |
| 839 | /* +1 to take label len + label string */ |
| 840 | label_len += 1; |
| 841 | |
| 842 | memcpy(dest, reader, label_len); |
| 843 | |
| 844 | dest += label_len; |
| 845 | nb_bytes += label_len; |
| 846 | reader += label_len; |
| 847 | } |
| 848 | |
| 849 | out: |
| 850 | /* offset computation: |
| 851 | * parse from <name> until finding either NULL or a pointer "c0xx" |
| 852 | */ |
| 853 | reader = name; |
| 854 | *offset = 0; |
| 855 | while (reader < bufend) { |
| 856 | if ((reader[0] & 0xc0) == 0xc0) { |
| 857 | *offset += 2; |
| 858 | break; |
| 859 | } |
| 860 | else if (*reader == 0) { |
| 861 | *offset += 1; |
| 862 | break; |
| 863 | } |
| 864 | *offset += 1; |
| 865 | ++reader; |
| 866 | } |
| 867 | |
| 868 | return nb_bytes; |
| 869 | |
| 870 | out_error: |
| 871 | return 0; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 872 | } |
| 873 | |
| 874 | /* |
| 875 | * Function to validate that the buffer DNS response provided in <resp> and |
| 876 | * finishing before <bufend> is valid from a DNS protocol point of view. |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 877 | * |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 878 | * The result is stored in <resolution>' response, buf_response, response_query_records |
| 879 | * and response_answer_records members. |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 880 | * |
| 881 | * This function returns one of the DNS_RESP_* code to indicate the type of |
| 882 | * error found. |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 883 | */ |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 884 | int dns_validate_dns_response(unsigned char *resp, unsigned char *bufend, struct dns_resolution *resolution) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 885 | { |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 886 | unsigned char *reader; |
| 887 | char *previous_dname, tmpname[DNS_MAX_NAME_SIZE]; |
| 888 | int len, flags, offset, ret; |
| 889 | int dns_query_record_id, dns_answer_record_id; |
Baptiste Assmann | 69fce67 | 2017-05-04 08:37:45 +0200 | [diff] [blame] | 890 | int nb_saved_records; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 891 | struct dns_query_item *dns_query; |
| 892 | struct dns_answer_item *dns_answer_record; |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 893 | struct dns_response_packet *dns_p; |
| 894 | struct chunk *dns_response_buffer; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 895 | |
| 896 | reader = resp; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 897 | len = 0; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 898 | previous_dname = NULL; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 899 | |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 900 | /* initialization of response buffer and structure */ |
| 901 | dns_p = &resolution->response; |
| 902 | dns_response_buffer = &resolution->response_buffer; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 903 | memset(dns_p, '\0', sizeof(struct dns_response_packet)); |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 904 | chunk_reset(dns_response_buffer); |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 905 | |
| 906 | /* query id */ |
| 907 | if (reader + 2 >= bufend) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 908 | return DNS_RESP_INVALID; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 909 | dns_p->header.id = reader[0] * 256 + reader[1]; |
| 910 | reader += 2; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 911 | |
| 912 | /* |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 913 | * flags and rcode are stored over 2 bytes |
Baptiste Assmann | 3440f0d | 2015-09-02 22:08:38 +0200 | [diff] [blame] | 914 | * First byte contains: |
| 915 | * - response flag (1 bit) |
| 916 | * - opcode (4 bits) |
| 917 | * - authoritative (1 bit) |
| 918 | * - truncated (1 bit) |
| 919 | * - recursion desired (1 bit) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 920 | */ |
Baptiste Assmann | 3440f0d | 2015-09-02 22:08:38 +0200 | [diff] [blame] | 921 | if (reader + 2 >= bufend) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 922 | return DNS_RESP_INVALID; |
| 923 | |
Baptiste Assmann | 3440f0d | 2015-09-02 22:08:38 +0200 | [diff] [blame] | 924 | flags = reader[0] * 256 + reader[1]; |
| 925 | |
| 926 | if (flags & DNS_FLAG_TRUNCATED) |
| 927 | return DNS_RESP_TRUNCATED; |
| 928 | |
| 929 | if ((flags & DNS_FLAG_REPLYCODE) != DNS_RCODE_NO_ERROR) { |
| 930 | if ((flags & DNS_FLAG_REPLYCODE) == DNS_RCODE_NX_DOMAIN) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 931 | return DNS_RESP_NX_DOMAIN; |
Baptiste Assmann | 3440f0d | 2015-09-02 22:08:38 +0200 | [diff] [blame] | 932 | else if ((flags & DNS_FLAG_REPLYCODE) == DNS_RCODE_REFUSED) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 933 | return DNS_RESP_REFUSED; |
| 934 | |
| 935 | return DNS_RESP_ERROR; |
| 936 | } |
| 937 | |
Baptiste Assmann | 3440f0d | 2015-09-02 22:08:38 +0200 | [diff] [blame] | 938 | /* move forward 2 bytes for flags */ |
| 939 | reader += 2; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 940 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 941 | /* 2 bytes for question count */ |
| 942 | if (reader + 2 >= bufend) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 943 | return DNS_RESP_INVALID; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 944 | dns_p->header.qdcount = reader[0] * 256 + reader[1]; |
| 945 | /* (for now) we send one query only, so we expect only one in the response too */ |
| 946 | if (dns_p->header.qdcount != 1) |
| 947 | return DNS_RESP_QUERY_COUNT_ERROR; |
| 948 | if (dns_p->header.qdcount > DNS_MAX_QUERY_RECORDS) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 949 | return DNS_RESP_INVALID; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 950 | reader += 2; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 951 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 952 | /* 2 bytes for answer count */ |
| 953 | if (reader + 2 >= bufend) |
| 954 | return DNS_RESP_INVALID; |
| 955 | dns_p->header.ancount = reader[0] * 256 + reader[1]; |
| 956 | if (dns_p->header.ancount == 0) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 957 | return DNS_RESP_ANCOUNT_ZERO; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 958 | /* check if too many records are announced */ |
| 959 | if (dns_p->header.ancount > DNS_MAX_ANSWER_RECORDS) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 960 | return DNS_RESP_INVALID; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 961 | reader += 2; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 962 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 963 | /* 2 bytes authority count */ |
| 964 | if (reader + 2 >= bufend) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 965 | return DNS_RESP_INVALID; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 966 | dns_p->header.nscount = reader[0] * 256 + reader[1]; |
| 967 | reader += 2; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 968 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 969 | /* 2 bytes additional count */ |
| 970 | if (reader + 2 >= bufend) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 971 | return DNS_RESP_INVALID; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 972 | dns_p->header.arcount = reader[0] * 256 + reader[1]; |
| 973 | reader += 2; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 974 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 975 | /* parsing dns queries */ |
| 976 | LIST_INIT(&dns_p->query_list); |
| 977 | for (dns_query_record_id = 0; dns_query_record_id < dns_p->header.qdcount; dns_query_record_id++) { |
| 978 | /* use next pre-allocated dns_query_item after ensuring there is |
| 979 | * still one available. |
| 980 | * It's then added to our packet query list. |
| 981 | */ |
| 982 | if (dns_query_record_id > DNS_MAX_QUERY_RECORDS) |
| 983 | return DNS_RESP_INVALID; |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 984 | dns_query = &resolution->response_query_records[dns_query_record_id]; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 985 | LIST_ADDQ(&dns_p->query_list, &dns_query->list); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 986 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 987 | /* name is a NULL terminated string in our case, since we have |
| 988 | * one query per response and the first one can't be compressed |
| 989 | * (using the 0x0c format) |
| 990 | */ |
| 991 | offset = 0; |
| 992 | len = dns_read_name(resp, bufend, reader, dns_query->name, DNS_MAX_NAME_SIZE, &offset); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 993 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 994 | if (len == 0) |
| 995 | return DNS_RESP_INVALID; |
| 996 | |
| 997 | reader += offset; |
| 998 | previous_dname = dns_query->name; |
| 999 | |
| 1000 | /* move forward 2 bytes for question type */ |
| 1001 | if (reader + 2 >= bufend) |
| 1002 | return DNS_RESP_INVALID; |
| 1003 | dns_query->type = reader[0] * 256 + reader[1]; |
| 1004 | reader += 2; |
| 1005 | |
| 1006 | /* move forward 2 bytes for question class */ |
| 1007 | if (reader + 2 >= bufend) |
| 1008 | return DNS_RESP_INVALID; |
| 1009 | dns_query->class = reader[0] * 256 + reader[1]; |
| 1010 | reader += 2; |
| 1011 | } |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1012 | |
| 1013 | /* now parsing response records */ |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1014 | LIST_INIT(&dns_p->answer_list); |
Baptiste Assmann | 69fce67 | 2017-05-04 08:37:45 +0200 | [diff] [blame] | 1015 | nb_saved_records = 0; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1016 | for (dns_answer_record_id = 0; dns_answer_record_id < dns_p->header.ancount; dns_answer_record_id++) { |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1017 | if (reader >= bufend) |
| 1018 | return DNS_RESP_INVALID; |
| 1019 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1020 | /* pull next response record from the list, if still one available, then add it |
| 1021 | * to the record list */ |
| 1022 | if (dns_answer_record_id > DNS_MAX_ANSWER_RECORDS) |
| 1023 | return DNS_RESP_INVALID; |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 1024 | dns_answer_record = &resolution->response_answer_records[dns_answer_record_id]; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1025 | LIST_ADDQ(&dns_p->answer_list, &dns_answer_record->list); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1026 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1027 | offset = 0; |
| 1028 | len = dns_read_name(resp, bufend, reader, tmpname, DNS_MAX_NAME_SIZE, &offset); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1029 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1030 | if (len == 0) |
| 1031 | return DNS_RESP_INVALID; |
| 1032 | |
| 1033 | /* check if the current record dname is valid. |
| 1034 | * previous_dname points either to queried dname or last CNAME target |
| 1035 | */ |
| 1036 | if (memcmp(previous_dname, tmpname, len) != 0) { |
| 1037 | if (dns_answer_record_id == 0) { |
| 1038 | /* first record, means a mismatch issue between queried dname |
| 1039 | * and dname found in the first record */ |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1040 | return DNS_RESP_INVALID; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1041 | } else { |
| 1042 | /* if not the first record, this means we have a CNAME resolution |
| 1043 | * error */ |
| 1044 | return DNS_RESP_CNAME_ERROR; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1045 | } |
| 1046 | |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1047 | } |
| 1048 | |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 1049 | dns_answer_record->name = chunk_newstr(dns_response_buffer); |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1050 | if (dns_answer_record->name == NULL) |
| 1051 | return DNS_RESP_INVALID; |
Baptiste Assmann | 5d681ba | 2015-10-15 15:23:28 +0200 | [diff] [blame] | 1052 | |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 1053 | ret = chunk_strncat(dns_response_buffer, tmpname, len); |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1054 | if (ret == 0) |
| 1055 | return DNS_RESP_INVALID; |
Baptiste Assmann | 2359ff1 | 2015-08-07 11:24:05 +0200 | [diff] [blame] | 1056 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1057 | reader += offset; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1058 | if (reader >= bufend) |
| 1059 | return DNS_RESP_INVALID; |
| 1060 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1061 | if (reader >= bufend) |
| 1062 | return DNS_RESP_INVALID; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1063 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1064 | /* 2 bytes for record type (A, AAAA, CNAME, etc...) */ |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1065 | if (reader + 2 > bufend) |
| 1066 | return DNS_RESP_INVALID; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1067 | dns_answer_record->type = reader[0] * 256 + reader[1]; |
| 1068 | reader += 2; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1069 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1070 | /* 2 bytes for class (2) */ |
| 1071 | if (reader + 2 > bufend) |
| 1072 | return DNS_RESP_INVALID; |
| 1073 | dns_answer_record->class = reader[0] * 256 + reader[1]; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1074 | reader += 2; |
| 1075 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1076 | /* 4 bytes for ttl (4) */ |
| 1077 | if (reader + 4 > bufend) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1078 | return DNS_RESP_INVALID; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1079 | dns_answer_record->ttl = reader[0] * 16777216 + reader[1] * 65536 |
| 1080 | + reader[2] * 256 + reader[3]; |
| 1081 | reader += 4; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1082 | |
| 1083 | /* now reading data len */ |
| 1084 | if (reader + 2 > bufend) |
| 1085 | return DNS_RESP_INVALID; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1086 | dns_answer_record->data_len = reader[0] * 256 + reader[1]; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1087 | |
| 1088 | /* move forward 2 bytes for data len */ |
| 1089 | reader += 2; |
| 1090 | |
| 1091 | /* analyzing record content */ |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1092 | switch (dns_answer_record->type) { |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1093 | case DNS_RTYPE_A: |
| 1094 | /* ipv4 is stored on 4 bytes */ |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1095 | if (dns_answer_record->data_len != 4) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1096 | return DNS_RESP_INVALID; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1097 | dns_answer_record->address.sa_family = AF_INET; |
| 1098 | memcpy(&(((struct sockaddr_in *)&dns_answer_record->address)->sin_addr), |
| 1099 | reader, dns_answer_record->data_len); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1100 | break; |
| 1101 | |
| 1102 | case DNS_RTYPE_CNAME: |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1103 | /* check if this is the last record and update the caller about the status: |
| 1104 | * no IP could be found and last record was a CNAME. Could be triggered |
| 1105 | * by a wrong query type |
| 1106 | * |
| 1107 | * + 1 because dns_answer_record_id starts at 0 while number of answers |
| 1108 | * is an integer and starts at 1. |
| 1109 | */ |
| 1110 | if (dns_answer_record_id + 1 == dns_p->header.ancount) |
| 1111 | return DNS_RESP_CNAME_ERROR; |
| 1112 | |
| 1113 | offset = 0; |
| 1114 | len = dns_read_name(resp, bufend, reader, tmpname, DNS_MAX_NAME_SIZE, &offset); |
| 1115 | |
| 1116 | if (len == 0) |
| 1117 | return DNS_RESP_INVALID; |
| 1118 | |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 1119 | dns_answer_record->target = chunk_newstr(dns_response_buffer); |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1120 | if (dns_answer_record->target == NULL) |
| 1121 | return DNS_RESP_INVALID; |
| 1122 | |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 1123 | ret = chunk_strncat(dns_response_buffer, tmpname, len); |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1124 | if (ret == 0) |
| 1125 | return DNS_RESP_INVALID; |
| 1126 | |
| 1127 | previous_dname = dns_answer_record->target; |
| 1128 | |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1129 | break; |
| 1130 | |
| 1131 | case DNS_RTYPE_AAAA: |
| 1132 | /* ipv6 is stored on 16 bytes */ |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1133 | if (dns_answer_record->data_len != 16) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1134 | return DNS_RESP_INVALID; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1135 | dns_answer_record->address.sa_family = AF_INET6; |
| 1136 | memcpy(&(((struct sockaddr_in6 *)&dns_answer_record->address)->sin6_addr), |
| 1137 | reader, dns_answer_record->data_len); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1138 | break; |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1139 | |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1140 | } /* switch (record type) */ |
| 1141 | |
Baptiste Assmann | 69fce67 | 2017-05-04 08:37:45 +0200 | [diff] [blame] | 1142 | /* increment the counter for number of records saved into our local response */ |
| 1143 | nb_saved_records += 1; |
| 1144 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1145 | /* move forward dns_answer_record->data_len for analyzing next record in the response */ |
| 1146 | reader += dns_answer_record->data_len; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1147 | } /* for i 0 to ancount */ |
| 1148 | |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1149 | /* let's add a last \0 to close our last string */ |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 1150 | ret = chunk_strncat(dns_response_buffer, "\0", 1); |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1151 | if (ret == 0) |
| 1152 | return DNS_RESP_INVALID; |
Baptiste Assmann | 96972bc | 2015-09-09 00:46:58 +0200 | [diff] [blame] | 1153 | |
Baptiste Assmann | 69fce67 | 2017-05-04 08:37:45 +0200 | [diff] [blame] | 1154 | /* save the number of records we really own */ |
| 1155 | dns_p->header.ancount = nb_saved_records; |
| 1156 | |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1157 | return DNS_RESP_VALID; |
| 1158 | } |
| 1159 | |
| 1160 | /* |
| 1161 | * search dn_name resolution in resp. |
| 1162 | * If existing IP not found, return the first IP matching family_priority, |
| 1163 | * otherwise, first ip found |
| 1164 | * The following tasks are the responsibility of the caller: |
Baptiste Assmann | 3cf7f98 | 2016-04-17 22:43:26 +0200 | [diff] [blame] | 1165 | * - <dns_p> contains an error free DNS response |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1166 | * For both cases above, dns_validate_dns_response is required |
| 1167 | * returns one of the DNS_UPD_* code |
| 1168 | */ |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1169 | #define DNS_MAX_IP_REC 20 |
Baptiste Assmann | fb7091e | 2017-05-03 15:43:12 +0200 | [diff] [blame] | 1170 | int dns_get_ip_from_response(struct dns_response_packet *dns_p, |
Baptiste Assmann | 4274637 | 2017-05-03 12:12:02 +0200 | [diff] [blame] | 1171 | struct dns_options *dns_opts, void *currentip, |
Thierry Fournier | ada3484 | 2016-02-17 21:25:09 +0100 | [diff] [blame] | 1172 | short currentip_sin_family, |
Baptiste Assmann | fb7091e | 2017-05-03 15:43:12 +0200 | [diff] [blame] | 1173 | void **newip, short *newip_sin_family, |
| 1174 | void *owner) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1175 | { |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1176 | struct dns_answer_item *record; |
Thierry Fournier | ada3484 | 2016-02-17 21:25:09 +0100 | [diff] [blame] | 1177 | int family_priority; |
Baptiste Assmann | 3cf7f98 | 2016-04-17 22:43:26 +0200 | [diff] [blame] | 1178 | int i, currentip_found; |
| 1179 | unsigned char *newip4, *newip6; |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1180 | struct { |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1181 | void *ip; |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1182 | unsigned char type; |
| 1183 | } rec[DNS_MAX_IP_REC]; |
| 1184 | int currentip_sel; |
| 1185 | int j; |
| 1186 | int rec_nb = 0; |
| 1187 | int score, max_score; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1188 | |
Baptiste Assmann | 4274637 | 2017-05-03 12:12:02 +0200 | [diff] [blame] | 1189 | family_priority = dns_opts->family_prio; |
Baptiste Assmann | 3cf7f98 | 2016-04-17 22:43:26 +0200 | [diff] [blame] | 1190 | *newip = newip4 = newip6 = NULL; |
| 1191 | currentip_found = 0; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1192 | *newip_sin_family = AF_UNSPEC; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1193 | |
| 1194 | /* now parsing response records */ |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 1195 | list_for_each_entry(record, &dns_p->answer_list, list) { |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1196 | /* analyzing record content */ |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1197 | switch (record->type) { |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1198 | case DNS_RTYPE_A: |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1199 | /* Store IPv4, only if some room is avalaible. */ |
| 1200 | if (rec_nb < DNS_MAX_IP_REC) { |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1201 | rec[rec_nb].ip = &(((struct sockaddr_in *)&record->address)->sin_addr); |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1202 | rec[rec_nb].type = AF_INET; |
| 1203 | rec_nb++; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1204 | } |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1205 | break; |
| 1206 | |
Baptiste Assmann | 3cf7f98 | 2016-04-17 22:43:26 +0200 | [diff] [blame] | 1207 | /* we're looking for IPs only. CNAME validation is done when |
| 1208 | * parsing the response buffer for the first time */ |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1209 | case DNS_RTYPE_CNAME: |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1210 | break; |
| 1211 | |
| 1212 | case DNS_RTYPE_AAAA: |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1213 | /* Store IPv6, only if some room is avalaible. */ |
| 1214 | if (rec_nb < DNS_MAX_IP_REC) { |
Baptiste Assmann | c1ce5f3 | 2016-05-14 11:26:22 +0200 | [diff] [blame] | 1215 | rec[rec_nb].ip = &(((struct sockaddr_in6 *)&record->address)->sin6_addr); |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1216 | rec[rec_nb].type = AF_INET6; |
| 1217 | rec_nb++; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1218 | } |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1219 | break; |
| 1220 | |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1221 | } /* switch (record type) */ |
Baptiste Assmann | bcbd491 | 2016-04-18 19:42:57 +0200 | [diff] [blame] | 1222 | } /* list for each record entries */ |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1223 | |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1224 | /* Select an IP regarding configuration preference. |
| 1225 | * Top priority is the prefered network ip version, |
| 1226 | * second priority is the prefered network. |
| 1227 | * the last priority is the currently used IP, |
| 1228 | * |
| 1229 | * For these three priorities, a score is calculated. The |
| 1230 | * weight are: |
Baptiste | fc72590 | 2016-12-26 23:21:08 +0100 | [diff] [blame] | 1231 | * 8 - prefered netwok ip version. |
| 1232 | * 4 - prefered network. |
| 1233 | * 2 - if the ip in the record is not affected to any other server in the same backend (duplication) |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1234 | * 1 - current ip. |
| 1235 | * The result with the biggest score is returned. |
| 1236 | */ |
| 1237 | max_score = -1; |
| 1238 | for (i = 0; i < rec_nb; i++) { |
Baptiste | fc72590 | 2016-12-26 23:21:08 +0100 | [diff] [blame] | 1239 | int record_ip_already_affected = 0; |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1240 | |
| 1241 | score = 0; |
| 1242 | |
| 1243 | /* Check for prefered ip protocol. */ |
| 1244 | if (rec[i].type == family_priority) |
Baptiste | fc72590 | 2016-12-26 23:21:08 +0100 | [diff] [blame] | 1245 | score += 8; |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1246 | |
| 1247 | /* Check for prefered network. */ |
Baptiste Assmann | 4274637 | 2017-05-03 12:12:02 +0200 | [diff] [blame] | 1248 | for (j = 0; j < dns_opts->pref_net_nb; j++) { |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1249 | |
| 1250 | /* Compare only the same adresses class. */ |
Baptiste Assmann | 4274637 | 2017-05-03 12:12:02 +0200 | [diff] [blame] | 1251 | if (dns_opts->pref_net[j].family != rec[i].type) |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1252 | continue; |
| 1253 | |
| 1254 | if ((rec[i].type == AF_INET && |
Willy Tarreau | eec1d38 | 2016-07-13 11:59:39 +0200 | [diff] [blame] | 1255 | in_net_ipv4(rec[i].ip, |
Baptiste Assmann | 4274637 | 2017-05-03 12:12:02 +0200 | [diff] [blame] | 1256 | &dns_opts->pref_net[j].mask.in4, |
| 1257 | &dns_opts->pref_net[j].addr.in4)) || |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1258 | (rec[i].type == AF_INET6 && |
Willy Tarreau | eec1d38 | 2016-07-13 11:59:39 +0200 | [diff] [blame] | 1259 | in_net_ipv6(rec[i].ip, |
Baptiste Assmann | 4274637 | 2017-05-03 12:12:02 +0200 | [diff] [blame] | 1260 | &dns_opts->pref_net[j].mask.in6, |
| 1261 | &dns_opts->pref_net[j].addr.in6))) { |
Baptiste | fc72590 | 2016-12-26 23:21:08 +0100 | [diff] [blame] | 1262 | score += 4; |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1263 | break; |
| 1264 | } |
| 1265 | } |
| 1266 | |
Baptiste Assmann | fb7091e | 2017-05-03 15:43:12 +0200 | [diff] [blame] | 1267 | /* Check if the IP found in the record is already affected to a member of a group. |
| 1268 | * If yes, the score should be incremented by 2. |
| 1269 | */ |
| 1270 | if (owner) { |
| 1271 | if (snr_check_ip_callback(owner, rec[i].ip, &rec[i].type)) |
Baptiste | fc72590 | 2016-12-26 23:21:08 +0100 | [diff] [blame] | 1272 | record_ip_already_affected = 1; |
Baptiste | fc72590 | 2016-12-26 23:21:08 +0100 | [diff] [blame] | 1273 | } |
Baptiste Assmann | fb7091e | 2017-05-03 15:43:12 +0200 | [diff] [blame] | 1274 | if (record_ip_already_affected == 0) |
Baptiste | fc72590 | 2016-12-26 23:21:08 +0100 | [diff] [blame] | 1275 | score += 2; |
| 1276 | |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1277 | /* Check for current ip matching. */ |
| 1278 | if (rec[i].type == currentip_sin_family && |
| 1279 | ((currentip_sin_family == AF_INET && |
Willy Tarreau | eec1d38 | 2016-07-13 11:59:39 +0200 | [diff] [blame] | 1280 | memcmp(rec[i].ip, currentip, 4) == 0) || |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1281 | (currentip_sin_family == AF_INET6 && |
| 1282 | memcmp(rec[i].ip, currentip, 16) == 0))) { |
| 1283 | score += 1; |
| 1284 | currentip_sel = 1; |
| 1285 | } else |
| 1286 | currentip_sel = 0; |
| 1287 | |
Baptiste | fc72590 | 2016-12-26 23:21:08 +0100 | [diff] [blame] | 1288 | |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1289 | /* Keep the address if the score is better than the previous |
Baptiste | fc72590 | 2016-12-26 23:21:08 +0100 | [diff] [blame] | 1290 | * score. The maximum score is 15, if this value is reached, |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1291 | * we break the parsing. Implicitly, this score is reached |
| 1292 | * the ip selected is the current ip. |
| 1293 | */ |
| 1294 | if (score > max_score) { |
| 1295 | if (rec[i].type == AF_INET) |
| 1296 | newip4 = rec[i].ip; |
| 1297 | else |
| 1298 | newip6 = rec[i].ip; |
| 1299 | currentip_found = currentip_sel; |
Baptiste | fc72590 | 2016-12-26 23:21:08 +0100 | [diff] [blame] | 1300 | if (score == 15) |
Thierry Fournier | ac88cfe | 2016-02-17 22:05:30 +0100 | [diff] [blame] | 1301 | return DNS_UPD_NO; |
| 1302 | max_score = score; |
| 1303 | } |
| 1304 | } |
| 1305 | |
Baptiste Assmann | 0453a1d | 2015-09-09 00:51:08 +0200 | [diff] [blame] | 1306 | /* no IP found in the response */ |
| 1307 | if (!newip4 && !newip6) { |
| 1308 | return DNS_UPD_NO_IP_FOUND; |
| 1309 | } |
| 1310 | |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1311 | /* case when the caller looks first for an IPv4 address */ |
| 1312 | if (family_priority == AF_INET) { |
| 1313 | if (newip4) { |
| 1314 | *newip = newip4; |
| 1315 | *newip_sin_family = AF_INET; |
| 1316 | if (currentip_found == 1) |
| 1317 | return DNS_UPD_NO; |
Baptiste Assmann | 8ea0bcc | 2017-05-04 08:24:11 +0200 | [diff] [blame] | 1318 | goto return_DNS_UPD_SRVIP_NOT_FOUND; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1319 | } |
| 1320 | else if (newip6) { |
| 1321 | *newip = newip6; |
| 1322 | *newip_sin_family = AF_INET6; |
| 1323 | if (currentip_found == 1) |
| 1324 | return DNS_UPD_NO; |
Baptiste Assmann | 8ea0bcc | 2017-05-04 08:24:11 +0200 | [diff] [blame] | 1325 | goto return_DNS_UPD_SRVIP_NOT_FOUND; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1326 | } |
| 1327 | } |
| 1328 | /* case when the caller looks first for an IPv6 address */ |
| 1329 | else if (family_priority == AF_INET6) { |
| 1330 | if (newip6) { |
| 1331 | *newip = newip6; |
| 1332 | *newip_sin_family = AF_INET6; |
| 1333 | if (currentip_found == 1) |
| 1334 | return DNS_UPD_NO; |
Baptiste Assmann | 8ea0bcc | 2017-05-04 08:24:11 +0200 | [diff] [blame] | 1335 | goto return_DNS_UPD_SRVIP_NOT_FOUND; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1336 | } |
| 1337 | else if (newip4) { |
| 1338 | *newip = newip4; |
| 1339 | *newip_sin_family = AF_INET; |
| 1340 | if (currentip_found == 1) |
| 1341 | return DNS_UPD_NO; |
Baptiste Assmann | 8ea0bcc | 2017-05-04 08:24:11 +0200 | [diff] [blame] | 1342 | goto return_DNS_UPD_SRVIP_NOT_FOUND; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1343 | } |
| 1344 | } |
| 1345 | /* case when the caller have no preference (we prefer IPv6) */ |
| 1346 | else if (family_priority == AF_UNSPEC) { |
| 1347 | if (newip6) { |
| 1348 | *newip = newip6; |
| 1349 | *newip_sin_family = AF_INET6; |
| 1350 | if (currentip_found == 1) |
| 1351 | return DNS_UPD_NO; |
Baptiste Assmann | 8ea0bcc | 2017-05-04 08:24:11 +0200 | [diff] [blame] | 1352 | goto return_DNS_UPD_SRVIP_NOT_FOUND; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1353 | } |
| 1354 | else if (newip4) { |
| 1355 | *newip = newip4; |
| 1356 | *newip_sin_family = AF_INET; |
| 1357 | if (currentip_found == 1) |
| 1358 | return DNS_UPD_NO; |
Baptiste Assmann | 8ea0bcc | 2017-05-04 08:24:11 +0200 | [diff] [blame] | 1359 | goto return_DNS_UPD_SRVIP_NOT_FOUND; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1360 | } |
| 1361 | } |
| 1362 | |
| 1363 | /* no reason why we should change the server's IP address */ |
| 1364 | return DNS_UPD_NO; |
Baptiste Assmann | 8ea0bcc | 2017-05-04 08:24:11 +0200 | [diff] [blame] | 1365 | |
| 1366 | return_DNS_UPD_SRVIP_NOT_FOUND: |
| 1367 | list_for_each_entry(record, &dns_p->answer_list, list) { |
| 1368 | /* move the first record to the end of the list, for internal round robin */ |
| 1369 | if (record) { |
| 1370 | LIST_DEL(&record->list); |
| 1371 | LIST_ADDQ(&dns_p->answer_list, &record->list); |
| 1372 | break; |
| 1373 | } |
| 1374 | } |
| 1375 | return DNS_UPD_SRVIP_NOT_FOUND; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1376 | } |
| 1377 | |
| 1378 | /* |
| 1379 | * returns the query id contained in a DNS response |
| 1380 | */ |
Thiago Farina | b1af23e | 2016-01-20 23:46:34 +0100 | [diff] [blame] | 1381 | unsigned short dns_response_get_query_id(unsigned char *resp) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1382 | { |
| 1383 | /* read the query id from the response */ |
| 1384 | return resp[0] * 256 + resp[1]; |
| 1385 | } |
| 1386 | |
| 1387 | /* |
| 1388 | * used during haproxy's init phase |
| 1389 | * parses resolvers sections and initializes: |
| 1390 | * - task (time events) for each resolvers section |
| 1391 | * - the datagram layer (network IO events) for each nameserver |
Baptiste Assmann | 5cd1b92 | 2017-02-02 22:44:15 +0100 | [diff] [blame] | 1392 | * It takes one argument: |
| 1393 | * - close_first takes 2 values: 0 or 1. If 1, the connection is closed first. |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1394 | * returns: |
| 1395 | * 0 in case of error |
| 1396 | * 1 when no error |
| 1397 | */ |
Baptiste Assmann | 5cd1b92 | 2017-02-02 22:44:15 +0100 | [diff] [blame] | 1398 | int dns_init_resolvers(int close_socket) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1399 | { |
| 1400 | struct dns_resolvers *curr_resolvers; |
| 1401 | struct dns_nameserver *curnameserver; |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1402 | struct dns_resolution *resolution, *res_back; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1403 | struct dgram_conn *dgram; |
| 1404 | struct task *t; |
| 1405 | int fd; |
| 1406 | |
Baptiste Assmann | fa4a663 | 2017-05-04 09:05:00 +0200 | [diff] [blame] | 1407 | /* initialize our DNS resolution cache */ |
| 1408 | dns_lru_tree = lru64_new(dns_cache_size); |
| 1409 | |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1410 | /* give a first random value to our dns query_id seed */ |
| 1411 | dns_query_id_seed = random(); |
| 1412 | |
| 1413 | /* run through the resolvers section list */ |
| 1414 | list_for_each_entry(curr_resolvers, &dns_resolvers, list) { |
| 1415 | /* create the task associated to the resolvers section */ |
| 1416 | if ((t = task_new()) == NULL) { |
| 1417 | Alert("Starting [%s] resolvers: out of memory.\n", curr_resolvers->id); |
| 1418 | return 0; |
| 1419 | } |
| 1420 | |
| 1421 | /* update task's parameters */ |
| 1422 | t->process = dns_process_resolve; |
| 1423 | t->context = curr_resolvers; |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1424 | t->expire = 0; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1425 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1426 | /* no need to keep the new task if one is already affected to our resolvers |
| 1427 | * section */ |
| 1428 | if (!curr_resolvers->t) |
| 1429 | curr_resolvers->t = t; |
| 1430 | else |
| 1431 | task_free(t); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1432 | |
| 1433 | list_for_each_entry(curnameserver, &curr_resolvers->nameserver_list, list) { |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1434 | dgram = NULL; |
Baptiste Assmann | 5cd1b92 | 2017-02-02 22:44:15 +0100 | [diff] [blame] | 1435 | |
| 1436 | if (close_socket == 1) { |
| 1437 | if (curnameserver->dgram) { |
Frédéric Lécaille | 6492053 | 2017-05-12 09:57:15 +0200 | [diff] [blame] | 1438 | fd_delete(curnameserver->dgram->t.sock.fd); |
Baptiste Assmann | 5cd1b92 | 2017-02-02 22:44:15 +0100 | [diff] [blame] | 1439 | memset(curnameserver->dgram, '\0', sizeof(*dgram)); |
| 1440 | dgram = curnameserver->dgram; |
| 1441 | } |
| 1442 | } |
| 1443 | |
| 1444 | /* allocate memory only if it has not already been allocated |
| 1445 | * by a previous call to this function */ |
| 1446 | if (!dgram && (dgram = calloc(1, sizeof(*dgram))) == NULL) { |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1447 | Alert("Starting [%s/%s] nameserver: out of memory.\n", curr_resolvers->id, |
| 1448 | curnameserver->id); |
| 1449 | return 0; |
| 1450 | } |
| 1451 | /* update datagram's parameters */ |
| 1452 | dgram->owner = (void *)curnameserver; |
| 1453 | dgram->data = &resolve_dgram_cb; |
| 1454 | |
| 1455 | /* create network UDP socket for this nameserver */ |
Frédéric Lécaille | 5e5bc9f | 2017-04-11 08:46:37 +0200 | [diff] [blame] | 1456 | if ((fd = socket(curnameserver->addr.ss_family, SOCK_DGRAM, IPPROTO_UDP)) == -1) { |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1457 | Alert("Starting [%s/%s] nameserver: can't create socket.\n", curr_resolvers->id, |
| 1458 | curnameserver->id); |
| 1459 | free(dgram); |
| 1460 | dgram = NULL; |
| 1461 | return 0; |
| 1462 | } |
| 1463 | |
| 1464 | /* "connect" the UDP socket to the name server IP */ |
Baptiste Assmann | 8c62c47 | 2015-09-21 20:55:08 +0200 | [diff] [blame] | 1465 | if (connect(fd, (struct sockaddr*)&curnameserver->addr, get_addr_len(&curnameserver->addr)) == -1) { |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1466 | Alert("Starting [%s/%s] nameserver: can't connect socket.\n", curr_resolvers->id, |
| 1467 | curnameserver->id); |
| 1468 | close(fd); |
| 1469 | free(dgram); |
| 1470 | dgram = NULL; |
| 1471 | return 0; |
| 1472 | } |
| 1473 | |
| 1474 | /* make the socket non blocking */ |
| 1475 | fcntl(fd, F_SETFL, O_NONBLOCK); |
| 1476 | |
| 1477 | /* add the fd in the fd list and update its parameters */ |
| 1478 | fd_insert(fd); |
| 1479 | fdtab[fd].owner = dgram; |
| 1480 | fdtab[fd].iocb = dgram_fd_handler; |
| 1481 | fd_want_recv(fd); |
| 1482 | dgram->t.sock.fd = fd; |
| 1483 | |
| 1484 | /* update nameserver's datagram property */ |
| 1485 | curnameserver->dgram = dgram; |
| 1486 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1487 | continue; |
| 1488 | } |
| 1489 | |
| 1490 | if (close_socket == 0) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1491 | continue; |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1492 | |
| 1493 | /* now, we can trigger DNS resolution */ |
| 1494 | list_for_each_entry_safe(resolution, res_back, &curr_resolvers->resolution.wait, list) { |
| 1495 | /* if there is no requester in the wait queue, no need to trigger the resolution */ |
| 1496 | if (LIST_ISEMPTY(&resolution->requester.wait)) |
| 1497 | continue; |
| 1498 | |
| 1499 | dns_trigger_resolution(resolution); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1500 | } |
| 1501 | |
| 1502 | /* task can be queued */ |
| 1503 | task_queue(t); |
| 1504 | } |
| 1505 | |
| 1506 | return 1; |
| 1507 | } |
| 1508 | |
| 1509 | /* |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1510 | * Allocate a pool of resolution to a resolvers section. |
| 1511 | * Each resolution is associated with a UUID. |
| 1512 | * |
| 1513 | * Return code: |
| 1514 | * - 0 if everything went smoothly |
| 1515 | * - -1 if an error occured |
| 1516 | */ |
| 1517 | int dns_alloc_resolution_pool(struct dns_resolvers *resolvers) |
| 1518 | { |
| 1519 | int i; |
| 1520 | struct dns_resolution *resolution; |
| 1521 | |
| 1522 | /* return if a pool has already been set for this resolvers */ |
| 1523 | if (!LIST_ISEMPTY(&resolvers->resolution.pool)) { |
| 1524 | return 0; |
| 1525 | } |
| 1526 | |
| 1527 | for (i = 0; i < resolvers->resolution_pool_size; i++) { |
| 1528 | resolution = dns_alloc_resolution(); |
| 1529 | if (!resolution) { |
| 1530 | Alert("Starting [%s] resolvers: can't allocate memory for DNS resolution pool.\n", resolvers->id); |
| 1531 | return -1; |
| 1532 | } |
| 1533 | resolution->uuid = i; |
| 1534 | LIST_ADDQ(&resolvers->resolution.pool, &resolution->list); |
| 1535 | } |
| 1536 | |
| 1537 | return 0; |
| 1538 | } |
| 1539 | |
| 1540 | /* |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1541 | * Forge a DNS query. It needs the following information from the caller: |
| 1542 | * - <query_id>: the DNS query id corresponding to this query |
| 1543 | * - <query_type>: DNS_RTYPE_* request DNS record type (A, AAAA, ANY, etc...) |
| 1544 | * - <hostname_dn>: hostname in domain name format |
| 1545 | * - <hostname_dn_len>: length of <hostname_dn> |
| 1546 | * To store the query, the caller must pass a buffer <buf> and its size <bufsize> |
| 1547 | * |
| 1548 | * the DNS query is stored in <buf> |
| 1549 | * returns: |
| 1550 | * -1 if <buf> is too short |
| 1551 | */ |
| 1552 | int dns_build_query(int query_id, int query_type, char *hostname_dn, int hostname_dn_len, char *buf, int bufsize) |
| 1553 | { |
| 1554 | struct dns_header *dns; |
Vincent Bernat | 9b7125c | 2016-04-08 22:17:45 +0200 | [diff] [blame] | 1555 | struct dns_question qinfo; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1556 | char *ptr, *bufend; |
| 1557 | |
| 1558 | memset(buf, '\0', bufsize); |
| 1559 | ptr = buf; |
| 1560 | bufend = buf + bufsize; |
| 1561 | |
| 1562 | /* check if there is enough room for DNS headers */ |
| 1563 | if (ptr + sizeof(struct dns_header) >= bufend) |
| 1564 | return -1; |
| 1565 | |
| 1566 | /* set dns query headers */ |
| 1567 | dns = (struct dns_header *)ptr; |
| 1568 | dns->id = (unsigned short) htons(query_id); |
Nenad Merdanovic | 8ab7942 | 2016-07-13 14:03:43 +0200 | [diff] [blame] | 1569 | dns->flags = htons(0x0100); /* qr=0, opcode=0, aa=0, tc=0, rd=1, ra=0, z=0, rcode=0 */ |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1570 | dns->qdcount = htons(1); /* 1 question */ |
| 1571 | dns->ancount = 0; |
| 1572 | dns->nscount = 0; |
| 1573 | dns->arcount = 0; |
| 1574 | |
| 1575 | /* move forward ptr */ |
| 1576 | ptr += sizeof(struct dns_header); |
| 1577 | |
| 1578 | /* check if there is enough room for query hostname */ |
| 1579 | if ((ptr + hostname_dn_len) >= bufend) |
| 1580 | return -1; |
| 1581 | |
| 1582 | /* set up query hostname */ |
| 1583 | memcpy(ptr, hostname_dn, hostname_dn_len); |
| 1584 | ptr[hostname_dn_len + 1] = '\0'; |
| 1585 | |
| 1586 | /* move forward ptr */ |
| 1587 | ptr += (hostname_dn_len + 1); |
| 1588 | |
| 1589 | /* check if there is enough room for query hostname*/ |
| 1590 | if (ptr + sizeof(struct dns_question) >= bufend) |
| 1591 | return -1; |
| 1592 | |
| 1593 | /* set up query info (type and class) */ |
Vincent Bernat | 9b7125c | 2016-04-08 22:17:45 +0200 | [diff] [blame] | 1594 | qinfo.qtype = htons(query_type); |
| 1595 | qinfo.qclass = htons(DNS_RCLASS_IN); |
| 1596 | memcpy(ptr, &qinfo, sizeof(qinfo)); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1597 | |
| 1598 | ptr += sizeof(struct dns_question); |
| 1599 | |
| 1600 | return ptr - buf; |
| 1601 | } |
| 1602 | |
| 1603 | /* |
| 1604 | * turn a string into domain name label: |
| 1605 | * www.haproxy.org into 3www7haproxy3org |
| 1606 | * if dn memory is pre-allocated, you must provide its size in dn_len |
| 1607 | * if dn memory isn't allocated, dn_len must be set to 0. |
| 1608 | * In the second case, memory will be allocated. |
| 1609 | * in case of error, -1 is returned, otherwise, number of bytes copied in dn |
| 1610 | */ |
Willy Tarreau | 2100b49 | 2015-07-22 16:42:43 +0200 | [diff] [blame] | 1611 | char *dns_str_to_dn_label(const char *string, char *dn, int dn_len) |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1612 | { |
| 1613 | char *c, *d; |
| 1614 | int i, offset; |
| 1615 | |
| 1616 | /* offset between string size and theorical dn size */ |
| 1617 | offset = 1; |
| 1618 | |
| 1619 | /* |
| 1620 | * first, get the size of the string turned into its domain name version |
| 1621 | * This function also validates the string respect the RFC |
| 1622 | */ |
| 1623 | if ((i = dns_str_to_dn_label_len(string)) == -1) |
| 1624 | return NULL; |
| 1625 | |
| 1626 | /* yes, so let's check there is enough memory */ |
| 1627 | if (dn_len < i + offset) |
| 1628 | return NULL; |
| 1629 | |
Willy Tarreau | d69d6f3 | 2015-07-22 16:45:36 +0200 | [diff] [blame] | 1630 | i = strlen(string); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1631 | memcpy(dn + offset, string, i); |
| 1632 | dn[i + offset] = '\0'; |
| 1633 | /* avoid a '\0' at the beginning of dn string which may prevent the for loop |
| 1634 | * below from working. |
| 1635 | * Actually, this is the reason of the offset. */ |
| 1636 | dn[0] = '0'; |
| 1637 | |
| 1638 | for (c = dn; *c ; ++c) { |
| 1639 | /* c points to the first '0' char or a dot, which we don't want to read */ |
| 1640 | d = c + offset; |
| 1641 | i = 0; |
| 1642 | while (*d != '.' && *d) { |
| 1643 | i++; |
| 1644 | d++; |
| 1645 | } |
| 1646 | *c = i; |
| 1647 | |
| 1648 | c = d - 1; /* because of c++ of the for loop */ |
| 1649 | } |
| 1650 | |
| 1651 | return dn; |
| 1652 | } |
| 1653 | |
| 1654 | /* |
| 1655 | * compute and return the length of <string> it it were translated into domain name |
| 1656 | * label: |
| 1657 | * www.haproxy.org into 3www7haproxy3org would return 16 |
| 1658 | * NOTE: add +1 for '\0' when allocating memory ;) |
| 1659 | */ |
| 1660 | int dns_str_to_dn_label_len(const char *string) |
| 1661 | { |
| 1662 | return strlen(string) + 1; |
| 1663 | } |
| 1664 | |
| 1665 | /* |
| 1666 | * validates host name: |
| 1667 | * - total size |
| 1668 | * - each label size individually |
| 1669 | * returns: |
| 1670 | * 0 in case of error. If <err> is not NULL, an error message is stored there. |
| 1671 | * 1 when no error. <err> is left unaffected. |
| 1672 | */ |
| 1673 | int dns_hostname_validation(const char *string, char **err) |
| 1674 | { |
| 1675 | const char *c, *d; |
| 1676 | int i; |
| 1677 | |
| 1678 | if (strlen(string) > DNS_MAX_NAME_SIZE) { |
| 1679 | if (err) |
| 1680 | *err = DNS_TOO_LONG_FQDN; |
| 1681 | return 0; |
| 1682 | } |
| 1683 | |
| 1684 | c = string; |
| 1685 | while (*c) { |
| 1686 | d = c; |
| 1687 | |
| 1688 | i = 0; |
| 1689 | while (*d != '.' && *d && i <= DNS_MAX_LABEL_SIZE) { |
| 1690 | i++; |
| 1691 | if (!((*d == '-') || (*d == '_') || |
| 1692 | ((*d >= 'a') && (*d <= 'z')) || |
| 1693 | ((*d >= 'A') && (*d <= 'Z')) || |
| 1694 | ((*d >= '0') && (*d <= '9')))) { |
| 1695 | if (err) |
| 1696 | *err = DNS_INVALID_CHARACTER; |
| 1697 | return 0; |
| 1698 | } |
| 1699 | d++; |
| 1700 | } |
| 1701 | |
| 1702 | if ((i >= DNS_MAX_LABEL_SIZE) && (d[i] != '.')) { |
| 1703 | if (err) |
| 1704 | *err = DNS_LABEL_TOO_LONG; |
| 1705 | return 0; |
| 1706 | } |
| 1707 | |
| 1708 | if (*d == '\0') |
| 1709 | goto out; |
| 1710 | |
| 1711 | c = ++d; |
| 1712 | } |
| 1713 | out: |
| 1714 | return 1; |
| 1715 | } |
| 1716 | |
| 1717 | /* |
| 1718 | * 2 bytes random generator to generate DNS query ID |
| 1719 | */ |
| 1720 | uint16_t dns_rnd16(void) |
| 1721 | { |
| 1722 | dns_query_id_seed ^= dns_query_id_seed << 13; |
| 1723 | dns_query_id_seed ^= dns_query_id_seed >> 7; |
| 1724 | dns_query_id_seed ^= dns_query_id_seed << 17; |
| 1725 | return dns_query_id_seed; |
| 1726 | } |
| 1727 | |
| 1728 | |
| 1729 | /* |
| 1730 | * function called when a timeout occurs during name resolution process |
| 1731 | * if max number of tries is reached, then stop, otherwise, retry. |
| 1732 | */ |
| 1733 | struct task *dns_process_resolve(struct task *t) |
| 1734 | { |
| 1735 | struct dns_resolvers *resolvers = t->context; |
| 1736 | struct dns_resolution *resolution, *res_back; |
Baptiste Assmann | 060e573 | 2016-01-06 02:01:59 +0100 | [diff] [blame] | 1737 | int res_preferred_afinet, res_preferred_afinet6; |
Baptiste Assmann | 4274637 | 2017-05-03 12:12:02 +0200 | [diff] [blame] | 1738 | struct dns_options *dns_opts = NULL; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1739 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1740 | /* if both there is no resolution in the run queue, we can re-schedule a wake up */ |
| 1741 | if (LIST_ISEMPTY(&resolvers->resolution.curr)) { |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1742 | /* no first entry, so wake up was useless */ |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1743 | dns_update_resolvers_timeout(resolvers); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1744 | return t; |
| 1745 | } |
| 1746 | |
| 1747 | /* look for the first resolution which is not expired */ |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1748 | list_for_each_entry_safe(resolution, res_back, &resolvers->resolution.curr, list) { |
| 1749 | struct dns_requester *requester = NULL; |
| 1750 | |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1751 | /* when we find the first resolution in the future, then we can stop here */ |
| 1752 | if (tick_is_le(now_ms, resolution->last_sent_packet)) |
| 1753 | goto out; |
| 1754 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1755 | if (LIST_ISEMPTY(&resolution->requester.curr)) |
| 1756 | goto out; |
| 1757 | |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1758 | /* |
| 1759 | * if current resolution has been tried too many times and finishes in timeout |
| 1760 | * we update its status and remove it from the list |
| 1761 | */ |
Baptiste Assmann | f778bb4 | 2015-09-09 00:54:38 +0200 | [diff] [blame] | 1762 | if (resolution->try <= 0) { |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1763 | struct dns_requester *tmprequester; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1764 | /* clean up resolution information and remove from the list */ |
| 1765 | dns_reset_resolution(resolution); |
| 1766 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1767 | LIST_DEL(&resolution->list); |
| 1768 | LIST_ADDQ(&resolvers->resolution.wait, &resolution->list); |
| 1769 | |
| 1770 | if (resolution->status != RSLV_STATUS_TIMEOUT) { |
| 1771 | resolution->status = RSLV_STATUS_TIMEOUT; |
| 1772 | resolution->last_status_change = now_ms; |
| 1773 | } |
| 1774 | |
| 1775 | /* notify the result to the requesters */ |
| 1776 | list_for_each_entry_safe(requester, tmprequester, &resolution->requester.curr, list) { |
| 1777 | requester->requester_error_cb(requester, DNS_RESP_TIMEOUT); |
| 1778 | LIST_DEL(&requester->list); |
| 1779 | LIST_ADDQ(&resolution->requester.wait, &requester->list); |
| 1780 | } |
Baptiste Assmann | 382824c | 2016-01-06 01:53:46 +0100 | [diff] [blame] | 1781 | goto out; |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1782 | } |
| 1783 | |
Baptiste Assmann | f778bb4 | 2015-09-09 00:54:38 +0200 | [diff] [blame] | 1784 | resolution->try -= 1; |
| 1785 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1786 | /* running queue is empty, nothing to do but wait */ |
| 1787 | if (LIST_ISEMPTY(&resolution->requester.curr)) |
| 1788 | goto out; |
| 1789 | |
| 1790 | requester = LIST_NEXT(&resolution->requester.curr, struct dns_requester *, list); |
| 1791 | |
| 1792 | switch (obj_type(requester->requester)) { |
| 1793 | case OBJ_TYPE_SERVER: |
| 1794 | dns_opts = &(objt_server(requester->requester)->dns_opts); |
| 1795 | break; |
| 1796 | |
| 1797 | case OBJ_TYPE_NONE: |
| 1798 | default: |
| 1799 | /* clean up resolution information and remove from the list */ |
| 1800 | dns_reset_resolution(resolution); |
| 1801 | |
| 1802 | LIST_DEL(&resolution->list); |
| 1803 | LIST_ADDQ(&resolvers->resolution.wait, &resolution->list); |
| 1804 | |
| 1805 | /* notify the result to the requester */ |
| 1806 | requester->requester_error_cb(requester, DNS_RESP_INTERNAL); |
| 1807 | goto out; |
| 1808 | } |
Baptiste Assmann | 4274637 | 2017-05-03 12:12:02 +0200 | [diff] [blame] | 1809 | |
| 1810 | res_preferred_afinet = dns_opts->family_prio == AF_INET && resolution->query_type == DNS_RTYPE_A; |
| 1811 | res_preferred_afinet6 = dns_opts->family_prio == AF_INET6 && resolution->query_type == DNS_RTYPE_AAAA; |
Baptiste Assmann | 060e573 | 2016-01-06 02:01:59 +0100 | [diff] [blame] | 1812 | |
| 1813 | /* let's change the query type if needed */ |
| 1814 | if (res_preferred_afinet6) { |
| 1815 | /* fallback from AAAA to A */ |
| 1816 | resolution->query_type = DNS_RTYPE_A; |
| 1817 | } |
| 1818 | else if (res_preferred_afinet) { |
| 1819 | /* fallback from A to AAAA */ |
| 1820 | resolution->query_type = DNS_RTYPE_AAAA; |
| 1821 | } |
| 1822 | |
Baptiste Assmann | 382824c | 2016-01-06 01:53:46 +0100 | [diff] [blame] | 1823 | /* resend the DNS query */ |
| 1824 | dns_send_query(resolution); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1825 | |
Baptiste Assmann | 382824c | 2016-01-06 01:53:46 +0100 | [diff] [blame] | 1826 | /* check if we have more than one resolution in the list */ |
| 1827 | if (dns_check_resolution_queue(resolvers) > 1) { |
| 1828 | /* move the rsolution to the end of the list */ |
| 1829 | LIST_DEL(&resolution->list); |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1830 | LIST_ADDQ(&resolvers->resolution.curr, &resolution->list); |
Baptiste Assmann | 325137d | 2015-04-13 23:40:55 +0200 | [diff] [blame] | 1831 | } |
| 1832 | } |
| 1833 | |
| 1834 | out: |
| 1835 | dns_update_resolvers_timeout(resolvers); |
| 1836 | return t; |
| 1837 | } |
William Lallemand | 69e9644 | 2016-11-19 00:58:54 +0100 | [diff] [blame] | 1838 | |
Baptiste Assmann | fa4a663 | 2017-05-04 09:05:00 +0200 | [diff] [blame] | 1839 | /* |
| 1840 | * build a dns cache key composed as follow: |
| 1841 | * <query type>#<hostname in domain name format> |
| 1842 | * and store it into <str>. |
| 1843 | * It's up to the caller to allocate <buf> and to reset it. |
| 1844 | * The function returns NULL in case of error (IE <buf> too small) or a pointer |
| 1845 | * to buf if successful |
| 1846 | */ |
| 1847 | struct chunk * |
| 1848 | dns_cache_key(int query_type, char *hostname_dn, int hostname_dn_len, struct chunk *buf) |
| 1849 | { |
| 1850 | int len, size; |
| 1851 | char *str; |
| 1852 | |
| 1853 | str = buf->str; |
| 1854 | len = buf->len; |
| 1855 | size = buf->size; |
| 1856 | |
| 1857 | switch (query_type) { |
| 1858 | case DNS_RTYPE_A: |
| 1859 | if (len + 1 > size) |
| 1860 | return NULL; |
| 1861 | memcpy(&str[len], "A", 1); |
| 1862 | len += 1; |
| 1863 | break; |
| 1864 | case DNS_RTYPE_AAAA: |
| 1865 | if (len + 4 > size) |
| 1866 | return NULL; |
| 1867 | memcpy(&str[len], "AAAA", 4); |
| 1868 | len += 4; |
| 1869 | break; |
| 1870 | default: |
| 1871 | return NULL; |
| 1872 | } |
| 1873 | |
| 1874 | if (len + 1 > size) |
| 1875 | return NULL; |
| 1876 | memcpy(&str[len], "#", 1); |
| 1877 | len += 1; |
| 1878 | |
| 1879 | if (len + hostname_dn_len + 1 > size) // +1 for trailing zero |
| 1880 | return NULL; |
| 1881 | memcpy(&str[len], hostname_dn, hostname_dn_len); |
| 1882 | len += hostname_dn_len; |
| 1883 | str[len] = '\0'; |
| 1884 | |
| 1885 | return buf; |
| 1886 | } |
| 1887 | |
| 1888 | /* |
| 1889 | * returns a pointer to a cache entry which may still be considered as up to date |
| 1890 | * by the caller. |
| 1891 | * returns NULL if no entry can be found or if the data found is outdated. |
| 1892 | */ |
| 1893 | struct lru64 * |
| 1894 | dns_cache_lookup(int query_type, char *hostname_dn, int hostname_dn_len, int valid_period, void *cache_domain) { |
| 1895 | struct lru64 *elem = NULL; |
| 1896 | struct dns_resolution *resolution = NULL; |
| 1897 | struct dns_resolvers *resolvers = NULL; |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1898 | struct dns_requester *requester = NULL; |
Baptiste Assmann | fa4a663 | 2017-05-04 09:05:00 +0200 | [diff] [blame] | 1899 | int inter = 0; |
| 1900 | struct chunk *buf = get_trash_chunk(); |
| 1901 | struct chunk *tmp = NULL; |
| 1902 | |
| 1903 | if (!dns_lru_tree) |
| 1904 | return NULL; |
| 1905 | |
| 1906 | chunk_reset(buf); |
| 1907 | tmp = dns_cache_key(query_type, hostname_dn, hostname_dn_len, buf); |
| 1908 | if (tmp == NULL) |
| 1909 | return NULL; |
| 1910 | |
| 1911 | elem = lru64_lookup(XXH64(buf->str, buf->len, 1), dns_lru_tree, cache_domain, 1); |
| 1912 | |
| 1913 | if (!elem || !elem->data) |
| 1914 | return NULL; |
| 1915 | |
| 1916 | resolution = elem->data; |
| 1917 | |
| 1918 | /* since we can change the fqdn of a server at run time, it may happen that |
| 1919 | * we got an innacurate elem. |
| 1920 | * This is because resolution->hostname_dn points to (owner)->hostname_dn (which |
| 1921 | * may be changed at run time) |
| 1922 | */ |
| 1923 | if ((hostname_dn_len == resolution->hostname_dn_len) && |
| 1924 | (memcmp(hostname_dn, resolution->hostname_dn, hostname_dn_len) != 0)) { |
| 1925 | return NULL; |
| 1926 | } |
| 1927 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1928 | requester = LIST_NEXT(&resolution->requester.wait, struct dns_requester *, list); |
| 1929 | |
| 1930 | switch (obj_type(requester->requester)) { |
| 1931 | case OBJ_TYPE_SERVER: |
| 1932 | resolvers = objt_server(requester->requester)->resolvers; |
| 1933 | break; |
| 1934 | case OBJ_TYPE_NONE: |
| 1935 | default: |
| 1936 | return NULL; |
| 1937 | } |
Baptiste Assmann | fa4a663 | 2017-05-04 09:05:00 +0200 | [diff] [blame] | 1938 | |
| 1939 | if (!resolvers) |
| 1940 | return NULL; |
| 1941 | |
| 1942 | if (resolvers->hold.valid < valid_period) |
| 1943 | inter = resolvers->hold.valid; |
| 1944 | else |
| 1945 | inter = valid_period; |
| 1946 | |
| 1947 | if (!tick_is_expired(tick_add(resolution->last_resolution, inter), now_ms)) |
| 1948 | return elem; |
| 1949 | |
| 1950 | return NULL; |
| 1951 | } |
| 1952 | |
Willy Tarreau | 777b560 | 2016-12-16 18:06:26 +0100 | [diff] [blame] | 1953 | /* if an arg is found, it sets the resolvers section pointer into cli.p0 */ |
William Lallemand | 69e9644 | 2016-11-19 00:58:54 +0100 | [diff] [blame] | 1954 | static int cli_parse_stat_resolvers(char **args, struct appctx *appctx, void *private) |
| 1955 | { |
| 1956 | struct dns_resolvers *presolvers; |
| 1957 | |
| 1958 | if (*args[3]) { |
William Lallemand | 69e9644 | 2016-11-19 00:58:54 +0100 | [diff] [blame] | 1959 | list_for_each_entry(presolvers, &dns_resolvers, list) { |
| 1960 | if (strcmp(presolvers->id, args[3]) == 0) { |
Willy Tarreau | 777b560 | 2016-12-16 18:06:26 +0100 | [diff] [blame] | 1961 | appctx->ctx.cli.p0 = presolvers; |
William Lallemand | 69e9644 | 2016-11-19 00:58:54 +0100 | [diff] [blame] | 1962 | break; |
| 1963 | } |
| 1964 | } |
Willy Tarreau | 777b560 | 2016-12-16 18:06:26 +0100 | [diff] [blame] | 1965 | if (appctx->ctx.cli.p0 == NULL) { |
William Lallemand | 69e9644 | 2016-11-19 00:58:54 +0100 | [diff] [blame] | 1966 | appctx->ctx.cli.msg = "Can't find that resolvers section\n"; |
Willy Tarreau | 3b6e547 | 2016-11-24 15:53:53 +0100 | [diff] [blame] | 1967 | appctx->st0 = CLI_ST_PRINT; |
William Lallemand | 69e9644 | 2016-11-19 00:58:54 +0100 | [diff] [blame] | 1968 | return 1; |
| 1969 | } |
| 1970 | } |
Willy Tarreau | 3067bfa | 2016-12-05 14:50:15 +0100 | [diff] [blame] | 1971 | return 0; |
William Lallemand | 69e9644 | 2016-11-19 00:58:54 +0100 | [diff] [blame] | 1972 | } |
| 1973 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 1974 | /* |
| 1975 | * if <resolution> is provided, then the function skips the memory allocation part. |
| 1976 | * It does the linking only. |
| 1977 | * |
| 1978 | * if <resolution> is NULL, the function links a dns resolution to a requester: |
| 1979 | * - it allocates memory for the struct requester used to link |
| 1980 | * the resolution to the requester |
| 1981 | * - it configures the resolution if this is the first requester to be linked to it |
| 1982 | * - it updates the requester with a pointer to the resolution |
| 1983 | * |
| 1984 | * Return code: |
| 1985 | * - 0 if everything happened smoothly |
| 1986 | * - -1 if an error occured. Of course, no resolution is linked to the requester |
| 1987 | */ |
| 1988 | int dns_link_resolution(void *requester, int requester_type, struct dns_resolution *resolution) |
| 1989 | { |
| 1990 | struct dns_resolution *tmpresolution = NULL; |
| 1991 | struct dns_requester *tmprequester = NULL; |
| 1992 | struct dns_resolvers *resolvers = NULL; |
| 1993 | char *hostname_dn = NULL; |
| 1994 | int new_resolution; |
| 1995 | |
| 1996 | if (!resolution) { |
| 1997 | tmprequester = calloc(1, sizeof(*tmprequester)); |
| 1998 | if (!tmprequester) |
| 1999 | return -1; |
| 2000 | |
| 2001 | switch (requester_type) { |
| 2002 | case OBJ_TYPE_SERVER: |
| 2003 | tmprequester->requester = &((struct server *)requester)->obj_type; |
| 2004 | hostname_dn = objt_server(tmprequester->requester)->hostname_dn; |
| 2005 | resolvers = objt_server(tmprequester->requester)->resolvers; |
| 2006 | switch (objt_server(tmprequester->requester)->dns_opts.family_prio) { |
| 2007 | case AF_INET: |
| 2008 | tmprequester->prefered_query_type = DNS_RTYPE_A; |
| 2009 | break; |
| 2010 | default: |
| 2011 | tmprequester->prefered_query_type = DNS_RTYPE_AAAA; |
| 2012 | } |
| 2013 | |
| 2014 | break; |
| 2015 | case OBJ_TYPE_NONE: |
| 2016 | default: |
| 2017 | free(tmprequester); |
| 2018 | return -1; |
| 2019 | } |
| 2020 | |
| 2021 | /* get a resolution from the resolvers' wait queue or pool */ |
| 2022 | tmpresolution = dns_resolution_list_get(resolvers, hostname_dn, tmprequester->prefered_query_type); |
| 2023 | if (!tmpresolution) { |
| 2024 | free(tmprequester); |
| 2025 | return -1; |
| 2026 | } |
| 2027 | } |
| 2028 | else { |
| 2029 | tmpresolution = resolution; |
| 2030 | |
| 2031 | switch (requester_type) { |
| 2032 | case OBJ_TYPE_SERVER: |
| 2033 | tmprequester = ((struct server *)requester)->dns_requester; |
| 2034 | resolvers = ((struct server *)requester)->resolvers; |
| 2035 | break; |
| 2036 | case OBJ_TYPE_NONE: |
| 2037 | default: |
| 2038 | return -1; |
| 2039 | } |
| 2040 | } |
| 2041 | |
| 2042 | /* flag this resolution as NEW if applicable (not already linked to any requester). |
| 2043 | * this is required to decide which parameters we have to update on the resolution. |
| 2044 | * If new, it means we pulled up the resolution from the resolvers' pool. |
| 2045 | */ |
| 2046 | if (LIST_ISEMPTY(&tmpresolution->requester.wait)) { |
| 2047 | new_resolution = 1; |
| 2048 | } |
| 2049 | else |
| 2050 | new_resolution = 0; |
| 2051 | |
| 2052 | /* those parameters are related to the requester type */ |
| 2053 | switch (obj_type(tmprequester->requester)) { |
| 2054 | case OBJ_TYPE_SERVER: |
| 2055 | /* some parameters should be set only if the resolution is brand new */ |
| 2056 | if (new_resolution) { |
| 2057 | tmpresolution->query_type = tmprequester->prefered_query_type; |
| 2058 | tmpresolution->hostname_dn = objt_server(tmprequester->requester)->hostname_dn; |
| 2059 | tmpresolution->hostname_dn_len = objt_server(tmprequester->requester)->hostname_dn_len; |
| 2060 | } |
| 2061 | |
| 2062 | /* update requester as well, only if we just allocated it */ |
| 2063 | objt_server(tmprequester->requester)->resolution = tmpresolution; |
| 2064 | if (!resolution) { |
| 2065 | tmprequester->requester_cb = snr_resolution_cb; |
| 2066 | tmprequester->requester_error_cb = snr_resolution_error_cb; |
| 2067 | objt_server(tmprequester->requester)->dns_requester = tmprequester; |
| 2068 | } |
| 2069 | break; |
| 2070 | case OBJ_TYPE_NONE: |
| 2071 | default: |
| 2072 | free(tmprequester); |
| 2073 | return -1; |
| 2074 | } |
| 2075 | |
| 2076 | /* update some parameters only if this is a brand new resolution */ |
| 2077 | if (new_resolution) { |
| 2078 | /* move the resolution to the requesters' wait queue */ |
| 2079 | LIST_DEL(&tmpresolution->list); |
| 2080 | LIST_ADDQ(&resolvers->resolution.wait, &tmpresolution->list); |
| 2081 | |
| 2082 | tmpresolution->status = RSLV_STATUS_NONE; |
| 2083 | tmpresolution->step = RSLV_STEP_NONE; |
| 2084 | tmpresolution->revision = 1; |
| 2085 | } |
| 2086 | |
| 2087 | /* add the requester to the resolution's wait queue */ |
| 2088 | if (resolution) |
| 2089 | LIST_DEL(&tmprequester->list); |
| 2090 | LIST_ADDQ(&tmpresolution->requester.wait, &tmprequester->list); |
| 2091 | |
| 2092 | return 0; |
| 2093 | } |
| 2094 | |
| 2095 | /* |
| 2096 | * pick up an available resolution from the different resolution list associated to a resolvers section, |
| 2097 | * in this order: |
| 2098 | * 1. check in resolution.curr for the same hostname and query_type |
| 2099 | * 2. check in resolution.wait for the same hostname and query_type |
| 2100 | * 3. take an available resolution from resolution.pool |
| 2101 | * |
| 2102 | * return an available resolution, NULL if none found. |
| 2103 | */ |
| 2104 | struct dns_resolution *dns_resolution_list_get(struct dns_resolvers *resolvers, char *hostname_dn, int query_type) |
| 2105 | { |
| 2106 | struct dns_resolution *resolution, *tmpresolution; |
| 2107 | struct dns_requester *requester; |
| 2108 | |
| 2109 | /* search for same hostname and query type in resolution.curr */ |
| 2110 | list_for_each_entry_safe(resolution, tmpresolution, &resolvers->resolution.curr, list) { |
| 2111 | requester = NULL; |
| 2112 | |
| 2113 | if (!LIST_ISEMPTY(&resolution->requester.wait)) |
| 2114 | requester = LIST_NEXT(&resolution->requester.wait, struct dns_requester *, list); |
| 2115 | else if (!LIST_ISEMPTY(&resolution->requester.curr)) |
| 2116 | requester = LIST_NEXT(&resolution->requester.curr, struct dns_requester *, list); |
| 2117 | |
| 2118 | if (!requester) |
| 2119 | continue; |
| 2120 | |
| 2121 | if ((query_type == requester->prefered_query_type) && |
| 2122 | (strcmp(hostname_dn, resolution->hostname_dn) == 0)) { |
| 2123 | return resolution; |
| 2124 | } |
| 2125 | } |
| 2126 | |
| 2127 | /* search for same hostname and query type in resolution.wait */ |
| 2128 | list_for_each_entry_safe(resolution, tmpresolution, &resolvers->resolution.wait, list) { |
| 2129 | requester = NULL; |
| 2130 | |
| 2131 | if (!LIST_ISEMPTY(&resolution->requester.wait)) |
| 2132 | requester = LIST_NEXT(&resolution->requester.wait, struct dns_requester *, list); |
| 2133 | else if (!LIST_ISEMPTY(&resolution->requester.curr)) |
| 2134 | requester = LIST_NEXT(&resolution->requester.curr, struct dns_requester *, list); |
| 2135 | |
| 2136 | if (!requester) |
| 2137 | continue; |
| 2138 | |
| 2139 | if ((query_type == requester->prefered_query_type) && |
| 2140 | (strcmp(hostname_dn, resolution->hostname_dn) == 0)) { |
| 2141 | return resolution; |
| 2142 | } |
| 2143 | } |
| 2144 | |
| 2145 | /* take the first one (hopefully) from the pool */ |
| 2146 | list_for_each_entry_safe(resolution, tmpresolution, &resolvers->resolution.pool, list) { |
| 2147 | if (LIST_ISEMPTY(&resolution->requester.wait)) { |
| 2148 | return resolution; |
| 2149 | } |
| 2150 | } |
| 2151 | |
| 2152 | return NULL; |
| 2153 | } |
| 2154 | |
Baptiste Assmann | 81ed1a0 | 2017-05-03 10:11:44 +0200 | [diff] [blame] | 2155 | /* This function allocates memory for a DNS resolution structure. |
| 2156 | * It's up to the caller to set the parameters |
| 2157 | * Returns a pointer to the structure resolution or NULL if memory could |
| 2158 | * not be allocated. |
| 2159 | */ |
| 2160 | struct dns_resolution *dns_alloc_resolution(void) |
| 2161 | { |
| 2162 | struct dns_resolution *resolution = NULL; |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 2163 | char *buffer = NULL; |
Baptiste Assmann | 81ed1a0 | 2017-05-03 10:11:44 +0200 | [diff] [blame] | 2164 | |
| 2165 | resolution = calloc(1, sizeof(*resolution)); |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 2166 | buffer = calloc(1, global.tune.bufsize); |
Baptiste Assmann | 81ed1a0 | 2017-05-03 10:11:44 +0200 | [diff] [blame] | 2167 | |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 2168 | if (!resolution || !buffer) { |
| 2169 | free(buffer); |
Baptiste Assmann | 81ed1a0 | 2017-05-03 10:11:44 +0200 | [diff] [blame] | 2170 | free(resolution); |
| 2171 | return NULL; |
| 2172 | } |
| 2173 | |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 2174 | chunk_init(&resolution->response_buffer, buffer, global.tune.bufsize); |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 2175 | LIST_INIT(&resolution->requester.wait); |
| 2176 | LIST_INIT(&resolution->requester.curr); |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 2177 | |
Baptiste Assmann | 81ed1a0 | 2017-05-03 10:11:44 +0200 | [diff] [blame] | 2178 | return resolution; |
| 2179 | } |
| 2180 | |
| 2181 | /* This function free the memory allocated to a DNS resolution */ |
| 2182 | void dns_free_resolution(struct dns_resolution *resolution) |
| 2183 | { |
Baptiste Assmann | 729c901 | 2017-05-22 15:13:10 +0200 | [diff] [blame] | 2184 | chunk_destroy(&resolution->response_buffer); |
Baptiste Assmann | 81ed1a0 | 2017-05-03 10:11:44 +0200 | [diff] [blame] | 2185 | free(resolution); |
| 2186 | |
| 2187 | return; |
| 2188 | } |
| 2189 | |
Baptiste Assmann | 201c07f | 2017-05-22 15:17:15 +0200 | [diff] [blame] | 2190 | /* this function free a resolution from its requester(s) and move it back to the pool */ |
| 2191 | void dns_resolution_free(struct dns_resolvers *resolvers, struct dns_resolution *resolution) |
| 2192 | { |
| 2193 | struct dns_requester *requester, *tmprequester; |
| 2194 | |
| 2195 | /* clean up configuration */ |
| 2196 | dns_reset_resolution(resolution); |
| 2197 | resolution->hostname_dn = NULL; |
| 2198 | resolution->hostname_dn_len = 0; |
| 2199 | |
| 2200 | list_for_each_entry_safe(requester, tmprequester, &resolution->requester.wait, list) { |
| 2201 | LIST_DEL(&requester->list); |
| 2202 | } |
| 2203 | list_for_each_entry_safe(requester, tmprequester, &resolution->requester.curr, list) { |
| 2204 | LIST_DEL(&requester->list); |
| 2205 | } |
| 2206 | |
| 2207 | LIST_DEL(&resolution->list); |
| 2208 | LIST_ADDQ(&resolvers->resolution.pool, &resolution->list); |
| 2209 | |
| 2210 | return; |
| 2211 | } |
| 2212 | |
| 2213 | /* |
| 2214 | * this function remove a requester from a resolution |
| 2215 | * and takes care of all the consequences. |
| 2216 | * It also cleans up some parameters from the requester |
| 2217 | */ |
| 2218 | void dns_rm_requester_from_resolution(struct dns_requester *requester, struct dns_resolution *resolution) |
| 2219 | { |
| 2220 | char *hostname_dn; |
| 2221 | struct dns_requester *tmprequester; |
| 2222 | |
| 2223 | /* resolution is still used by other requesters, we need to move |
| 2224 | * some pointers to an other requester if needed |
| 2225 | */ |
| 2226 | switch (obj_type(requester->requester)) { |
| 2227 | case OBJ_TYPE_SERVER: |
| 2228 | hostname_dn = objt_server(requester->requester)->hostname_dn; |
| 2229 | break; |
| 2230 | case OBJ_TYPE_NONE: |
| 2231 | default: |
| 2232 | hostname_dn = NULL; |
| 2233 | break; |
| 2234 | } |
| 2235 | |
| 2236 | if (resolution->hostname_dn != hostname_dn) |
| 2237 | return; |
| 2238 | |
| 2239 | /* First, we need to find this other requester */ |
| 2240 | tmprequester = NULL; |
| 2241 | list_for_each_entry(tmprequester, &resolution->requester.wait, list) { |
| 2242 | if (tmprequester != requester) |
| 2243 | break; |
| 2244 | } |
| 2245 | if (!tmprequester) { |
| 2246 | /* if we can't find it in wait queue, let's get one in run queue */ |
| 2247 | list_for_each_entry(tmprequester, &resolution->requester.curr, list) { |
| 2248 | if (tmprequester != requester) |
| 2249 | break; |
| 2250 | } |
| 2251 | } |
| 2252 | |
| 2253 | /* move hostname_dn related pointers to the next requester */ |
| 2254 | switch (obj_type(tmprequester->requester)) { |
| 2255 | case OBJ_TYPE_SERVER: |
| 2256 | resolution->hostname_dn = objt_server(tmprequester->requester)->hostname_dn; |
| 2257 | resolution->hostname_dn_len = objt_server(tmprequester->requester)->hostname_dn_len; |
| 2258 | break; |
| 2259 | case OBJ_TYPE_NONE: |
| 2260 | default: |
| 2261 | ;; |
| 2262 | } |
| 2263 | |
| 2264 | |
| 2265 | /* clean up the requester */ |
| 2266 | LIST_DEL(&requester->list); |
| 2267 | switch (obj_type(requester->requester)) { |
| 2268 | case OBJ_TYPE_SERVER: |
| 2269 | objt_server(requester->requester)->resolution = NULL; |
| 2270 | break; |
| 2271 | case OBJ_TYPE_NONE: |
| 2272 | default: |
| 2273 | ;; |
| 2274 | } |
| 2275 | } |
| 2276 | |
Willy Tarreau | 777b560 | 2016-12-16 18:06:26 +0100 | [diff] [blame] | 2277 | /* This function dumps counters from all resolvers section and associated name |
| 2278 | * servers. It returns 0 if the output buffer is full and it needs to be called |
| 2279 | * again, otherwise non-zero. It may limit itself to the resolver pointed to by |
| 2280 | * <cli.p0> if it's not null. |
William Lallemand | 69e9644 | 2016-11-19 00:58:54 +0100 | [diff] [blame] | 2281 | */ |
| 2282 | static int cli_io_handler_dump_resolvers_to_buffer(struct appctx *appctx) |
| 2283 | { |
| 2284 | struct stream_interface *si = appctx->owner; |
| 2285 | struct dns_resolvers *presolvers; |
| 2286 | struct dns_nameserver *pnameserver; |
| 2287 | |
| 2288 | chunk_reset(&trash); |
| 2289 | |
| 2290 | switch (appctx->st2) { |
| 2291 | case STAT_ST_INIT: |
| 2292 | appctx->st2 = STAT_ST_LIST; /* let's start producing data */ |
| 2293 | /* fall through */ |
| 2294 | |
| 2295 | case STAT_ST_LIST: |
| 2296 | if (LIST_ISEMPTY(&dns_resolvers)) { |
| 2297 | chunk_appendf(&trash, "No resolvers found\n"); |
| 2298 | } |
| 2299 | else { |
| 2300 | list_for_each_entry(presolvers, &dns_resolvers, list) { |
Willy Tarreau | 777b560 | 2016-12-16 18:06:26 +0100 | [diff] [blame] | 2301 | if (appctx->ctx.cli.p0 != NULL && appctx->ctx.cli.p0 != presolvers) |
William Lallemand | 69e9644 | 2016-11-19 00:58:54 +0100 | [diff] [blame] | 2302 | continue; |
| 2303 | |
| 2304 | chunk_appendf(&trash, "Resolvers section %s\n", presolvers->id); |
| 2305 | list_for_each_entry(pnameserver, &presolvers->nameserver_list, list) { |
| 2306 | chunk_appendf(&trash, " nameserver %s:\n", pnameserver->id); |
| 2307 | chunk_appendf(&trash, " sent: %ld\n", pnameserver->counters.sent); |
| 2308 | chunk_appendf(&trash, " valid: %ld\n", pnameserver->counters.valid); |
| 2309 | chunk_appendf(&trash, " update: %ld\n", pnameserver->counters.update); |
| 2310 | chunk_appendf(&trash, " cname: %ld\n", pnameserver->counters.cname); |
| 2311 | chunk_appendf(&trash, " cname_error: %ld\n", pnameserver->counters.cname_error); |
| 2312 | chunk_appendf(&trash, " any_err: %ld\n", pnameserver->counters.any_err); |
| 2313 | chunk_appendf(&trash, " nx: %ld\n", pnameserver->counters.nx); |
| 2314 | chunk_appendf(&trash, " timeout: %ld\n", pnameserver->counters.timeout); |
| 2315 | chunk_appendf(&trash, " refused: %ld\n", pnameserver->counters.refused); |
| 2316 | chunk_appendf(&trash, " other: %ld\n", pnameserver->counters.other); |
| 2317 | chunk_appendf(&trash, " invalid: %ld\n", pnameserver->counters.invalid); |
| 2318 | chunk_appendf(&trash, " too_big: %ld\n", pnameserver->counters.too_big); |
| 2319 | chunk_appendf(&trash, " truncated: %ld\n", pnameserver->counters.truncated); |
| 2320 | chunk_appendf(&trash, " outdated: %ld\n", pnameserver->counters.outdated); |
| 2321 | } |
| 2322 | } |
| 2323 | } |
| 2324 | |
| 2325 | /* display response */ |
| 2326 | if (bi_putchk(si_ic(si), &trash) == -1) { |
| 2327 | /* let's try again later from this session. We add ourselves into |
| 2328 | * this session's users so that it can remove us upon termination. |
| 2329 | */ |
| 2330 | si->flags |= SI_FL_WAIT_ROOM; |
| 2331 | return 0; |
| 2332 | } |
| 2333 | |
| 2334 | appctx->st2 = STAT_ST_FIN; |
| 2335 | /* fall through */ |
| 2336 | |
| 2337 | default: |
| 2338 | appctx->st2 = STAT_ST_FIN; |
| 2339 | return 1; |
| 2340 | } |
| 2341 | } |
| 2342 | |
| 2343 | /* register cli keywords */ |
| 2344 | static struct cli_kw_list cli_kws = {{ },{ |
| 2345 | { { "show", "stat", "resolvers", NULL }, "show stat resolvers [id]: dumps counters from all resolvers section and\n" |
| 2346 | " associated name servers", |
| 2347 | cli_parse_stat_resolvers, cli_io_handler_dump_resolvers_to_buffer }, |
| 2348 | {{},} |
| 2349 | }}; |
| 2350 | |
| 2351 | |
| 2352 | __attribute__((constructor)) |
| 2353 | static void __dns_init(void) |
| 2354 | { |
| 2355 | cli_register_kw(&cli_kws); |
| 2356 | } |
| 2357 | |